This version uses the whole sha1sum:
#!/usr/bin/sh for fname in *.mp3; do mv "$fname" $(echo "$fname" | sha1sum | cut -f1 -d' ').mp3 done
This version uses only the first 8 characters of the sha1sum (WARNING: might overwrite files)
#!/usr/bin/sh for fname in *.mp3; do mv "$fname" $(echo "$fname" | sha1sum | cut -b -8).mp3 done