How do I control MIDI fades (crescendos and decrescendos) and MIDI volume within a file?

Both controllers 7 and 11 control volume. Controller 11 (Expression) controls the varying sound values within a track, while Controller 7 (Volume) controls the mixing of sound levels with other tracks. Other more complex methods may be required where sophisticated bend and othermodeling software is used. To obtain a fade, use Controller 11, not Controller 7. Volume should be controlled via the Mixer when ever possible. The advantage to having both a volume and an expression control is that it allows you to add dynamics to your song and still maintain the relative balance between different instruments. Ensure that all tracks have Controller 11 value 127 at the start which switches the Expression on fully each time the song is started from the beginning.  more