It's a fine line.
I saw Graham Townsend, the wonderful Canadian fiddler, agree to a request at the end of his set....he was asked to play "Orange Blossom Special", a tune he didn't usually do, but he shrugged and said he'd do it this once.....and the band who was due up next stood there with their jaws on their shoes as Graham just milked that tune for all it was worth! Not especially fast, but done as well as I've ever heard. He was clearly making a point, but the music did NOT suffer in the process.