Turn table speed variation question

I've always found that tracks containing sustained piano notes (chords mainly) seem to highlight the smallest variation in platter speed.

However, I do not notice the same speed variations with sustained notes played on any other instruments.

Works well when auditioning turntables, but a PITA when you hit those older, less than stellar recordings, where the tape machine cause the issue.

Wondered if anyone else had the same experience with a different instrument, or is this specific to the piano.

Thanks