Re MIDI from cassettes - there's another approach...

Record the tune onto your hard drive as a .WAV file, sample rate 11K, 8 bit mono, and you should have a wave file small enough to email. Send it to a few people (me, if you wish), who can MIDI it, then choose the version you like! Or is that too easy??!

If it's on CD, you could use MP3 software (if you have it!).

If I've assumed too much knowledge (I often do!), I can simplify the process if I know what sound recording software you have.