What do you do if you're performing in concert and the balance is off? You can take the approach one Woodstock performer did and say during a song, "A little less bottom end on the guitar, please," or sing, "Turn up the guitar," as another performer did at a different concert.
While some listeners might think this compromises the moment, I'd contend that having too much or too little of an instrument in the mix or vocals that are too soft or too loud compromises things more.
