MidiPro.org: Online Midi Editor & Player, MidiPro.org is the ONLY complete Online Midi Editor and Player. An unlimited number of tracks can be output to MP3 or WAV audio files. Import audio files and map them to Midi notes. Add Drum Loops, Reverb, 3-band EQ, ADSR Envelopes, Low-pass Filters, and LFO Modulators. It allows any synth to play 48 Microtones per octave. Edit the Pitch, Velocity, and Duration of every Midi Event. Copy, Transpose, Change Durations, and Change Velocities for Notes in any time Range. Add Controllers and Pitch Ben.