Rhapsody back in the day beat that. You could use All Music Guide info to build amazing custom playlists. Custom options like “Music featuring electric guitar with no vocals made between 1950-1957 with a tempo between 90-120” and it would shoot out a whole playlist
For vocalists in Western music traditions, the steps of a major scale (doesn’t matter the key) go by the names Do Re Mi Fa So La Ti Do instead of just 1 2 3 4 5 6 7 8 the way most other musicians refer to them.
They are saying that in the song ABC by the Jackson Five, the notes they sing in that relative key when they say “Do Re Mi” are actually “So La Do”