I recently replaced kitchen counter and used same sink and faucet. Now when using hot water the fixture "sings/whistles"? Only happens on hot side, cold is fine and never did this before. Any suggestions? Thanks,

Some of the plumbing experts may have a better idea, but my first thoughts are:

Shut-off valve not completely open
A piece of debris dislodged and is now stuck in the faucet

You might try disassembling the faucet as if you were replacing the seals and see if you find anything.

Good Luck,
WallyH

Wally... you may not be an expert... but I could not have said that better myself! Great advise!

Dratcliffe... check it out... let us know how it goes.