Share My Creation mp3muser

A small music tool to detect simple chord (maj, min, 7) and change speed in real time while playing a preloaded mp3 song. Although I have better chord analyzer tool for learning guitar, I want to make one to see how it works, and realized that even to detect simple chords is a quite hard job.

I am happy that B4J can make applications run quite fast for signal processing tasks and make UI much easier.


If you want to try: java -jar Mp3muser.jar (using java version "1.8.0_202", may have many bugs)


  • Mp3muser.jar
    460.9 KB · Views: 77


Active Member
Licensed User
Longtime User
After mp3 loaded the key of the song is identified with much better result then the chord detection. With key detected as a priori knowledge the chord detection could also be improved later.

BTW: I am using canvas for all drawings including buttons, I am confused on whether in B4J the canvas needs to be invalidated, seems not.

mp3muser key.png