psai® - Interactive Music Engine

psai® is the first dedicated Interactive Music Engine for videogames
available on Unity and PC.



Learn more!

Check it out!


Go to Unity Asset Store

MOUNT & BLADE 2 Gameplay (E3 2017)

MOUNT & BLADE 2 Gameplay (E3 2017)

What is psai®?

What is psai®?

The psai® Player

The psai® Player

psai® Tutorial: How psai® works

psai® Tutorial: How psai® works

psai® Tutorial: How to build a soundtrack from scratch

psai® Tutorial: How to build a soundtrack from scratch

psai® Tutorial: How to integrate your soundtrack into your Unity game

psai® Tutorial: How to integrate your soundtrack into your Unity game

psai® Tutorial: Unity Extension psai® Editor Light

psai® Tutorial: Unity Extension psai® Editor Light

psai® Tutorial: Angry Bots Demo 01 - Location Music

psai® Tutorial: Angry Bots Demo 01 - Location Music

psai® Tutorial: Angry Bots Demo 02 - Battle Music

psai® Tutorial: Angry Bots Demo 02 - Battle Music

psai® Tutorial: Angry Bots Demo 03 - Boss Fight

psai® Tutorial: Angry Bots Demo 03 - Boss Fight


psai® Player Demo

Play around with our demo soundtrack, using the psai® Player.

Watch the psai® Player Tutorial Video for an introduction.

Rollerball Demo

Roll up the ramp and hear the music getting more intense!

Watch the Unity Integration Tutorial Video to see how it was done.

Angry Bots Demo

Several interactive music features added to the Unity Demo Project "Angry Bots" using the psai® Demo Soundtrack.

Watch the 3 tutorial videos on "Location Music", "Battle Music" and "Boss Fight" to learn how it was done.



psai® Editor (Unity Edition)

psai® Editor (Win/Mac) 1.1.1 6,4 MB Requires psai® Music Engine Pro & Pro User Registration. If you have purchased psai® before Feb. 2015, you will automatically be registered Pro User. Please contact us:



psai® Demo Soundtrack zip 176 MB download
psai® 8 Free Music Themes zip 156 MB download



psai® Manual

Learn about psai®'s design concept and its playback logic.



API Documentation

API documentation for Unity and native (C++) version.

Unity API

Native API


Take a look into Unity's official forum to discuss and learn from other developers using psai®.



Learn how psai® works, how to build a soundtrack and how to integrate it into your game.


Check it out!
Control interactive music in your browser with our psai® live demos (Unity).


Download the psai® Editor standalone software and some demo tracks to mess around with.


Got stuck, need help?
Take a look into the manual, the API documentation and check out the forum.

What is psai®?

psai® is the first dedicated Interactive Music Engine on Unity. It enables developers to achieve highly interactive videogame music which adapts automatically to the gameplay, whilst making the process of creating and controlling the music as easy and convenient as possible.


Check out our introduction videos or demos for a hands-on experience!


In 2007, at the time we started working as audio service providers for videogames, we have been very much intrigued by the potential of adaptive videogame music. In collaboration with our clients we have strived towards creating interactive soundtracks which emotionally connect players with the gameplay and the story in order for them to have an intense movie-like experience.

Approaching the concepts of interactive music from a technical point of view, we realized pretty quickly that if you want to achieve truly complex adaptivity, the whole process of creating and then controlling the music soon gets enormously cumbersome. Which is why developers and composers often refrain from it - there have been simply no tools available which are powerful and easy to use at the same time.

That is what motivated us in 2008 to start putting our conceptual ideas for interactive videogame music and our experience as composers into the development of psai®. First we started developing a native version for PC which has since been successfully used in a number of commercial projects. In 2014 we finished porting psai® to the Unity game engine in order to make its features available to a larger audience. psai® for Unity is completely written in C# without any native code involved, so it works on all of Unity’s target platforms, both with the free and the professional version of Unity.

Latest News

psai 1.7.2 released

psai 1.7.2 is now available in the Unity Asset Store!

* psai now runs smoothly in WebGL
* added an optional AudioMixerGroup output for your psai music, so you can apply any of the audio effects that come with Unity 5!
* 3 ready-to-go Demo Scenes and integrated PsaiDemoSoundtrack, to get started quickly
* lots of minor fixes and improvements

psai 1.7.1 released

Hi everyone! psai 1.7.1 is out! Get it in the Unity Asset Store.


* the "Resource" subfolder containing your soundtrack can now be places anywhere, e.g.
"Assets/MySoundtrackFiles/Resources/MySoundtrack" would be a valid location.
* cleaned up PsaiCoreManager, added psai Master Volume slider
* fixed: the Log Level (the amount of logging information) can not be changed on-the-fly
* further minimized memory allocation at runtime

psai 1.7.0 released

hi all! psai 1.7.0 is now ready to download in the Unity Asset Store. It contains a whole lot of improvements to the playback logic and trigger scripts. Here's the full changelog:

* changed playback logic: BasicMoodAlteration and DramaticEvent will now return smoothly to the last Basic Mood.
* fixed playback logic for Shock
* fixed Psai.prefab UI not working outside the PsaiPlayer.scene
* Trigger script rework
* You can now not only trigger music Themes, but also let the music stop or return to the last Basic Mood
using any of the common Trigger scripts.
* replaced PsaiStopMusic() by PsaiTriggerOnSignal()
* removed PsaiGenericTrigger()
* removed PsaiOneShotTrigger()
* fixed PsaiTriggerOnButtonDown()
* Trigger editor rework
* all Triggers are now automatically synchronized by PsaiCoreManager
* added option to force immediate interruption, regardless of Theme Types
* added option for deactivation after firing once
* added option to override default fadeout time when stopping the music immediately
* removed from Psai

Ready-to-go music packages available!

Hi there,

we have just released a first bunch of ready-to-go interactive music packages and single themes in the Unity Asset Store: "The Burrows" (Candy & Fun), "Ruins Of The Past" (Epic & Fantasy), "Thinking Fast" (Casual & Strategy), "Speedcowboys" (Rock & Racing), "Heroic Anthem" (Battle & Action). Check them out!!/search/psai


psai free version available

Hi everybody,

we have just released a free version of our Interactive Music Engine psai*. It has full runtime functionality so you can get psai and check out all its features within your game using our comprehensive Demo Soundtrack and the additional 8 Free Music Themes we provide. If you want to enrich your gameplay with highly interactive music, check it out!!/search/psai

*If you want to create interactive soundtracks from scratch, you need to purchase the psai Music Engine Pro, which includes the psai Editor standalone application.


Mount & Blade II - Bannerlord (WIP)

Mount & Blade II - Bannerlord (WIP)

In collaboration with Mount & Blade developer Taleworlds Entertainment and game audio specialists Dynamedion we have been creating a very unique psai® soundtrack. Historical medieval live instruments, a "Conan-like" orchestral maintheme and lots of thrilling battle music support the dense atmosphere of this epic game. We are very much looking forward to its release!

The Devil's Men (WIP)

The Devil's Men (WIP)

Our latest psai® project: In collaboration with the renowned German developer Daedalic Entertainment we are working on "The Devil's Men" - a storydriven adventure set in a world made of steampunk elements amidst a fictitious Victorian England. Platform: Unity

Black Mirror III

Black Mirror III

Our first commercial psai® release. It carries on the fabulous tradition of using adaptive music in point-and-click adventures.

Lost Chronicles of Zerzura

Lost Chronicles of Zerzura

Happy with what they achieved with psai® in their Black Mirror III game, developer Cranberry Production and publisher dtp entertainment decided to go for psai® also with their following release.

Legends of Pegasus

Legends of Pegasus

After two successful releases for which we contributed psai® music, it was time to let other composers work with psai®. Yes, it worked out well. :-)


General Questions

My audio middleware already supports interactive music. Why should I use psai?

psai® is a specialized tool for creating and controlling interactive music, its ease of use is unrivaled. psai® was designed by videogame composers, who found that the approaches of conventional game audio middleware to interactive music were too complicated and not flexible enough, so they could not achieve the desired level of adaptivity and dramaturgy. In most approaches to interactive music you need to manually define paths through your musical timeline, making the authoring process both tedious and error prone. With psai® you can achieve a more adaptive and and more complex interactive soundtrack without going gray. It also has some very unique features such as controlling music's intensity level, automatic recombination of segments and pausing, gameplay driven playback logic etc. which provide great potential for creating impressive interactive soundtracks for your game.

What's the difference between the regular/free version and the Pro version?

Both versions include the very same engine running in Unity. The Pro version however includes access to the psai® Editor standalone application.

With the psai® Music Engine Pro you get the full package enabling you to create psai® projects from scratch using the psai® Editor. In order to get full advantage of the Pro version you need to register as Pro user by email. Once you are registered Pro user you will receive the psai® Editor standalone software including any future updates.

By introducing the regular psai® Music Engine (engine without the editor) we wanted to make it easier for people to try out psai® within their own projects. You cannot create soundtracks from scratch but if you grab the Demo Soundtrack and the 8 Free Music Themes from the Unity Asset Store, you will will have a pretty comprehensive package to check out psai®. You can also use the regular version to run any purchased psai® music in your project.

I would like to check out psai. What's the easiest way to do so?

If you are a interested in checking out psai® you could

1. Either have a look at the psai® Demos which run directly in your browser (Unity plugin required).

2. Or you go to Unity Asset Store and check out psai® using your own game project or Unity's Angry Bots Demo.

Please have look into the psai® manual or watch our tutorial videos to learn more about psai®'s design concept.

Where do I get psai music from?

We often get asked where you can get psai music from. Here is a quick overview:
1. UNITY ASSET STORE: You can purchase ready-to-go psai music in Unity Asset Store. (Available very soon! We are working on it.) Using the psai music ingame requires the FREE psai music engine (!/content/29347). No extra costs.
2. SONIC LIBERTY: You can go to our partners at and purchase tracks there. Their catalogue of high quality music is huge, prices are decent, licensing is very simple and transparent. Once you have chosen your tracks, please let them know that you want to receive psai-compatible music themes. The music will be prepared for psai-use WITHOUT any extra charge, you are being charged regular prices. Using the psai music ingame requires the FREE psai music engine (!/content/29347). No extra costs.
3. PSAI EDITOR: You can create your own psai music using the psai editor. You need to purchase the psai music engine PRO from the Unity Asset Store to do so, current price is $45, it includes the psai editor standalone-application (!/content/24788). You can either use pre-existing tracks (you will need to segment them, we achieved awesome results working with pre-existing tracks) or you can compose custom tracks for psai-use (if you are into music or have a composer at hand).
In case you need any help with preparing tracks, extending or tuning your interactive music, feel free to contact us, we are able to help you at very reasonable rates.

Can I use psai for my SFX?

No, that doesn't make much sense. psai® was designed around the complex requirements of interactive music, which is much different from handling SFX. You may use psai® for SFX-like atmospheric background tracks, though.

Am I able to use my pre-existing mp3 tracks with psai?

Yes. You need to import them by using the psai® Editor but once this is done you will be able to use them in the same way you are used to from other tools. However, to benefit from psai's features you need to slice up your audio track in musical segments and classify their intensity, as shown in the tutorial videos.

Does psai for Unity run on all of Unity's target platforms?

Yes, psai® is completely written in C# without any native or platform-specific code.

Do customers get a DLL or the source code?

You get the full sourcecode. The only DLL that's internally referenced by psai is the .NET implementation for Google protobuf, written by Marc Gravell. The sourcecode is available here.

Does psai only suit „big“ epic games with lots of storytelling?

No. psai® suits any kind of game. Due to its simplicity, you may have a lot of fun using it for your puzzle game or your platformer as well. Choose a groovy playful track and use psai® to connect its intensity level to the elapsed time or any other element which is critical in your game. The psai® music will support your gameplay nicely. You also will for sure enjoy the increased musical variety due to psai®'s recombination of musical segments. No more boring loops!

Why does intensity level decrease automatically over time?

From a technical perspective, this approach makes it possible that you never have to worry about switching Themes on or off. Instead, you just place Trigger-Events in your game world, in a fire-and-forget-manner. When there are no Triggers firing, the music will eventually calm down.
From an emotional perspective: As we were discussing the basic design of psai® in an early phase of development we agreed that psai® first of all should be closely connected to principles of human emotions. The decreasing intensity is one of those basic principles. Think of a situation which upsets you: As soon as there are no more "triggers" - because you maybe left the room, ended the call, etc. - your emotion will very likely decrease over time and after a while you have forgotten what upset you in the first place. Same within games: If you are having an big-boss-encounter, it makes sense the music reflects your situation of having to face a dangerous threat (unless you are very well equipped and skilled ;-)). If you then decide to run instead of to fight, it also makes sense the music reflects your decreasing sense of threat until you are way out of reach. Once the whole action scenario is over the music should again go back to accompanying the current game setting by means of an appropriate background mood.

Why does psai use Theme Types? Am I restricted due to these?

No, you are not restricted by the psai® Theme Types. Here is why we came up with these: While using common tools on some of our first projects we quickly realized if you programm musical behaviour logic manually it is very likely that you go crazy especially if the project grows big: "If playing action_track_013 at intensity 85% and player leaves combat area, return to background theme cave_007, but not if the player has changed location in the meantime and found the magic staff, then play ...". So you see it's a matter of priorities and recurring rules the music has to follow - which are based on the principles of gameplay. The psai® Theme Types reflect these basic rules of musical behaviour and by using them you can free your mind from complicated logic issues but concentrate on making a great game. It's as simple as this: An Action Theme will always immediately interrupt a Basic Mood (background music), but not vice versa.

psai? What does it mean?

The name psai® was derived from its creators, Periscope Studio. It's an abbreviation of Periscope Studio Audio Intelligence. P.S. You should not mix it up with Portable Sanitation Association International.

Troubleshooting (psai® for Unity)

When i run my Scene, the PsaiPlayer shows "NO SOUNDTRACK LOADED"

Please make sure that..:
1. Your soundtrack has been built/exported to a location somewhere within the 'Assets/Resources/ ' folder of your Unity Project, like to "Assets/Resources/MySoundtrack". You can export either from the psai® Editor standalone application, or from the psai® Editor (Light Edition) in the 'Windows' menu within Unity.
2. In that directory mentioned above there needs to be a binary soundtrack file that holds all the playback configuration of your soundtrack, the default name is 'soundtrack.bytes'.
3. In your Scene there needs to be an instance of the 'Psai.prefab' that comes with the psai.unitypackage. Click its 'PsaiSoundtrackLoader' component and make sure the 'Path To Soundtrack Within Resources Folder' points to your soundtrack file. E.g. if your Project has been exported to "Assets/Resources/MySoundtrack/soundtrack.bytes", the path should hold "MySoundtrack/soundtrack". Use the slash '/' as the directory seperator on all platforms.

The PsaiPlayer shows a button for each Theme, but when i click i can't hear anything.

First check if the audio files can be found, which are referred to by the soundtrack.bytes file. To do so, make sure the Unity Editor is not running your Project (press Stop), then select the psai® object in the Hierarchy window and its PsaiCoreManager component. Make sure its LogLevel variable is set to 'errors'. Now run your Scene again and trigger a Theme by pressing its button. Now check the Console window for messages like 'Audio File not found'. If this is the case, most likely your Audio files have been deleted or moved to another directory, either already within your psai Project or later after exporting to Unity. The check that, open the psai® Editor (standalone), load the psai® Project and run the Project Audit command from the Project menu. If you get no errors, export to Unity again by clicking File > Build Soundtrack / Export to Unity.If you get errors "Audio File not found!" in the Project Audit, click the Segments marked red, select the 'Audio File' rider in the Segment Property Panel, and fix the relative path to the Audio File by clicking the "..." button.

Psai seems to play correctly, but i still can't hear anything / only very soft and mono.

Most likely the import settings of your audio files are not set up correctly within Unity. To check that, click one of the Audio Files in the Project window to have it displayed in the Inspector. There, among other settings the "3D" flag is checked by default, but for psai® it needs to be disabled. To do that quickly and easily, the psai.unitypackage comes with the "psai Multi Audio Object Editor" which can be accessed from the Project window by right-clicking on the parent folder that holds your soundtrack files. In the editor window make sure 'use psai settings' is checked and then just click the "Apply" button.


psai® for Unity

Get psai® from the Unity Asset Store and use it for all of your Unity projects without further costs or royalties. Companies need to purchase a single copy for each seat.

psai® native SDK (C++)

The native version of psai® is currently available for Windows only. Please contact us if you are interested in evaluating or licensing.


For licensing requests and other matters
please send an email to:

For technical support:

The psai® technology is a product of

Periscope Studio UG (haftungsbeschraenkt) & Co. KG
Stresemannstrasse 342
22761 Hamburg

Adrian Koch, Jan Werkmeister

Commercial register:
Company registration number: HRA 110405
Court of record: Amtsgericht Hamburg
Personally liable partner:
Periscope Studio Verwaltung UG (haftungsbeschraenkt)
Company registration number: HRB 110432
Court of record: Amtsgericht Hamburg

Tax number: 41/650/03662
VAT-ID number: DE267838155