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RapidComposer v5

Designed from the ground up for music composition.
Used by thousands of composers since 2010.

RapidComposer is a unique, non-destructive, phrase-based music prototyping software designed for composers, songwriters and musicians of all musical styles (for Windows and macOS: standalone, VST3, AU, AU MFX).

Latest News:
April 8, 2024: RapidComposer v5.2 released
October 16, 2023: RapidComposer v5.0 released! Read upgrade info

Music theory integrated

Music Theory Integrated

Create great sounding chord progressions, use piano-style phrases even if you’ve never touched a piano, auto-harmonize melodies, get chord suggestions, load MIDI files with chord detection, use the chord palette or the "circle of fifths" chart, RapidComposer will always assist you in songwriting.

Smart phrases

AI assistant

The AI assistant (in both full and light editions) is able to provide suggestions for chord replacements, chord progressions, chord rules, phrases, and even song structure and tracks depending on the genre and/or mood you specified. This feature uses OpenAI services (models like GPT-4) so an OpenAI API key is required for usage (more in the FAQ).

Smart phrases

Smart Phrases

Phrases always conform to the current chord and scale on the master track. Forget about tinkering with notes. Lay out the chords on the master track, or just drop a chord progression on it, with a key-press you can generate a harmony track with perfect voice leading. Start composing now!

Phrase Generators

Phrase Generators

Rhythm and phrase generators are included for various purposes. Create monophonic or polyphonic patterns. Generate melody. Use variations to change phrases non-destructively. Slice or change the rhythm of existing phrases.

Chord selection

Flexible Chord Selection

RapidComposer offers several ways to select chords for the master track or chord progressions including Tonnetz and Circle of Fifths. Color chord buttons by consonance, common notes, tonality or suggestions. Set up chord rules for progressions. Use chord voicings for tracks, phrases or master track chords.

Idea Tool

Idea Tool*

RapidComposer will generate a multi-track composition with chords based on your settings, using your phrases. Different types of workflows are supported. Not just when you are out of ideas.

* Full Edition only

Melody Editor

Melody Editor*

Melodya is a motive generator and editor, which was integrated into RapidComposer as a Melody Editor tab in v4.0. By enabling the chords track, you can create a melody for a given chord progression, so two entirely different workflows are supported.

* Full Edition only


Chord, Scale, Chord Progression Libraries

The large chord, scale and chord progression libraries are expandable. The docked browsers will let you search, preview, sort, group and display the items. A file browser and a CC envelope browser was added too.

Customizable UI

Customizable UI

The user interface and the keyboard shortcuts can be fully customized. Set your preferred colors, font size, button shapes, borders with several themes included. Scalable vector graphics is used, so the UI will look great with any font size. The UI looks the same on Windows or macOS and supports retina/HiDPI screens.

What Our Fantastic Users Say

Since our last conversation I've completed 3 songs for sync (one for a Master Card ad) I'm super happy. The past 4 days I've put close to 24 hours into the program. Actually Sunday this past, I was able to work in RapidComposer for like 8-10 hours with no issues. I was beaming! Oh..and from what I've seen and heard, Orb Composer doesn't hold a candle to RC :)

Foley Artist, Musician, Composer, Producer, Mixing Engineer 

"I currently own Cthulu, Scaler, Melody Sauce, Riffer, Captain Chords, and none of those can hold a candle to RapidComposer. I hope nobody else buys this because at the moment this is my Secret Weapon. It has raised my game to a whole new level. RapidComposer could change music as we know it especially for the Electronic Music Producer with little or no knowledge of Music Theory."

Musician, Composer, Producer 

"I often use the Melody Generator combined with a chords track, to spark ideas when I have complete writer's block. And sometimes I use the Idea Tool to come up with a random chord progression. I always come up with something cool and useful, even after experimenting for only 5 minutes."

Musician, Composer, Music Teacher 

"RapidComposer is the best tool in the world for making masterpiece music in less than 10 minutes. Finally, I have my one tool for writing REAL music."

"I have been a registered user of RapidComposer for years and I can honestly say that Attila never rests on constantly improving and adding refinements that truly make RapidComposer one of a kind. Please, keep up your hard work Mr Mezei it is much appreciated."

Robert Wiegert 
Producer, Composer

"RapidComposer is the most powerful compositional tool that I have used in over 20 years of producing music. I am able to create faster and more importantly to a higher level than ever before. It is function over form. Not pretty, but a huge amount of power lies under it's skin. If you are patient it offers huge reward. The price is very competitive and the Support from the developer, Attila is the best I have ever known. Anybody who makes music of any kind would be wise to give it a fair trial."

secondstep from KVRAudio Forum

"Rapid Composer is such a deep and inspiring tool that it is hard to put into words the joyful emotional affect it causes as you create music in a manner that is unlike any other program or DAW. It is very well designed and improved continuously by it's totally dedicated developer. There is some brilliance in this program! It has allowed me to develop music that I would not be able to otherwise with my limited knowledge of music theory. I totally recommend this program."

Philip Chance

"RapidComposer is a remarkable composition tool for musicians. It's often classified as a sequencer, which is technically accurate, but it's so much more! To quote another user, "The potential of this program is VAST." There are many cool built-in features and tricks designed to help musicians, producers, and songwriters compose songs. [...] Thank you MusicDevelopments for developing this fantastic creative environment."

Tommy Zai
Review on Gearslutz

"Breaking new ground, RapidComposer is an amazing [...] compositional tool - we're impressed! "

Computer Music Magazine
Computer Music Innovation Award, 2012 May

"RapidComposer is a fundamental rethink of every important aspect of computer composition. Structure and surface are wonderfully entangled in RapidComposer, casting a tool that puts ideas, form and texture at the forefront as never before."

Casey James Basichis
Composer - Cartoon Network

"RapidComposer is extremely efficient in workflow, as a composer I can sense the intuition behind the well thought layout and when I felt something was missing I discussed about it and some of my suggested features were implimented in hours !
Impeccable service is the cherry on top of the amazing software

Israel Roy
Composer, Mixing Engineer

"To me, RC is a tool that is always ready to help you create and combine backtracks harmonies and inspirational melodies very quickly.
Simply, import harmonies, phrases, rhythms from midi files to build libraries to your taste
and combine them to create your own as you wish!"

N. Yıldırım Sarıhan
Mixing Engineer, Composer 

"From a beginners point of view, RapidComposer is a very awesome, yet complex program. The more you delve into it, however, the more you can decide which direction you want to go with it. RapidComposer, can produce it's own song, but it really shines when you work with a generated midi file. The algorithms that are the heart and soul of the program, are second to none. You can tell that a lot of work went into this, a lot of development, tweaking and bolstering it up to the great program that it is. My advice to the beginner: if you get frustrated with RapidComposer, read the documents, watch the videos. It's too much to grasp in a session or two. You'll just be delighted, that you were patient enough and let RapidComposer work for you !"

Dale E. Krueger

"Thank you for developing and improving this app. I still don't see WHY this has not won an award. I looked at others but NONE of them give you this type of "under the hood" control. This is such a GREAT app. It's like a best friend, it gives ideas but leaves room for you to make the final choices. The Youtube videos help a lot to ease the learning curve of this app. But once you get it the composing is endless fun. Bravo!!"

Brent St. Clair
Singer, Composer

"Mit RapidComposer steht dem Anwender ein mächtiges und umfangreiches Werkzeug zur Verfügung, um schnell und einfach – auch ohne umfangreiche Kenntnisse in der Musiktheorie – gut klingende Musik zu entwerfen. [...] RapidComposer lässt sich für alle empfehlen, die ein wenig Hilfestellung bei der Komposition, ein Werkzeug für eine schnelle Musik-Skizze oder ein schnelles Ideen-Werkzeug für neue Inspirationen benötigen."

German BEAT Magazin, December 2019

"Since using RapidComposer to write compositions, I find myself writing more for orchestra and individual instruments. The tools from RapidComposer give me the ability to emulate and analyse great composers and explore directions in music."

Herbie van Tetering
Performing Composer, Berklee College of Music Alumnus


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