A website called in Bb 2.o features YouTube videos of various musicians playing in Bb major, allowing you to mix the videos' audio and listen to them blend together. You are also encouraged to jam along with them, and possibly videotape a performance to contribute to the experiment.
If you are a guitar player, here's a tablature sample of the Bb major scale (Bb C D Eb F G A), for you to improvise notes and play along with the other B-flat musicians. This example is in standard (low to high) E A D G B E tuning:
e|------------------------------------------------6--8--10--|
B|--------------------------------------6--8--10------------|
G|--------------------------------7--8----------------------|
D|----------------------7--8--10----------------------------|
A|------------6--8--10--------------------------------------|
E|--6--8--10------------------------------------------------|
