I almost always have a few suggestions for bands, mainly arrangement and vocal harmony issues, and I'll almost always suggest/setup totally different guitar tones. I beleive that as a producer it's my job to ensure that the band gets a good product. My first job is to figure out what they define as good. I've worked with crazy talented guitarist/singers/songwriters, and i expect them to have spectacular performances, so I keep my comments limited to their performance and tone. I've also worked with bands that can't write their way out of a wet paper bag, but play with an amazing amount of conviction and energy, and I'll make sure that we refine their songs and music into something that is more representative to the type of music they want to play. I've often told bands to take out a third verse, or come in with the vocals sooner etc. One perticular band I worked with had a tune that just wasn't working, and I was in the kitchen with the guitarist/singer over a coffee. He was playing the tune on an acoustic gutiar and singing along, trying to figure out another electric guitar part. I instantly realized that the song should have never been electric, it's an acoustic tune. We tracked it right then, told the bass player to bring in his upright and the drummer to bring his brushes. Bamm, a total succes, and everyone loves the song. I feel that as producers, we need to serve 4 things
1. The song
2. The artist
3. The audience
4. Ourselves (this is a very sticky point, and could also be # 1 in the list)
If you know that the band is not playing to their potential, or that their song isn't quite as refined as it should be, tell them, it's your job! They hired you because they wanted to make a good record, not because they wanted an engineer. Serve the music while keeping the band excited and happy, and throw the engineer a bone or two if he/she is good, (or a big bottle of whiskey if the band stinks, or and even bigger bottle if the band stinks and you're the engineer and producer!)
Take it or leave it, but this is my opinion!!
R