How loud do you like to play your music?

65 to 75 is pleasant over the long run if you are just listening. I agree with Shadorne on modern recordings and their use of compression.

Good uncompressed tracks that I use are Paul Kelly "May 1992" at 75 dbs and Midnight Oil's "Earth and Sun and Moon" and 90 dbs when I am tuning down my recording studio here in So Cal. Always sound incredible. Also love Willie Nelson's Teatro at 65 dbs. Love the drums on Joni Mitchell's Dreamland.

Albertporter: What is the app for the iPhone?

Calbrs03,
I recently got an I-phone myself and I think the app Albert's speaking of is called Decibel. I intend to add this to my phone as soon as I figure out how. My Radio Shack meter stopped working. I usually try to keep it at 85 or lower of I can help it by the way. Levels above 85 for prolonged periods are what studies seem to indicate are dangerous. How long is prolonged? I don't know.

Most of my music is acoustical jazz small combo ie quintets and sextets which usally includes a piano. My range is 65 to 80db with 85db plenty loud. I still want to hear fine music 20 years from now.

I should have said peak on dynamic recordings with the average RMS being lower.
I always set the volume too high for well recorded classical symphonic pieces. With rock and roll the bands seem to play it at one level only which is very loud and purposefully distorted. Those can have relatively constant/compressed sound levels.
Oddly its those rock or blue/rock which I will crank and even change the rig for. Nothing like Janis Joplin played at 70 db or the Delaware Destroyers played at Stardust volume. Never played Stardust intentionally louder 80-85 db.