Famous backing singers somehow mess up holding note (8)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

Anagram (somehow) of MESS UP , containing RE (a note in the musical sol-fa scale, as in do-re-mi). “Backing singers” is a little unfair: the group was originally “The Supremes” without a named lead singer, then briefly “Diana Ross and the Supremes”, and continued under their original name after Ross left.