Pretty self explanatory. I'm getting married in Sausalito, CA, which has a citywide noise ordinance of 55 dB. Because of this, we are not going to have a DJ, but we do plan on having a couple friends perform acoustic songs, and we want to have an iPod mix for the reception. Any suggestions for making sure we don't get too loud, and actually...any idea just how loud 55 dB is?? It can't be TOO quiet, or there would never be weddings there

Also, any suggestions for how to relay this to the guests?
Any advice is appreciated!!