Hey Gang!
Quite an interesting discussion going on here, so I thought I might add a slightly different perspective.
I am an independent musician with my own music label and I write songs/music that are intentionally aimed at scuba divers, parrotheads, Trop-Rock, whatever you want to call it. As such, I can honestly tell you that for myself it is quite flattering to have someone utilize your music in any kind of production. The ONLY requirement I would suggest is that you always give credit to the artist. Stick a little blurb on the screen at the end of your video giving credit to the artist and maybe even plug their website or something like that. At the very least, if you credit the artist's name somewhere in the production, people can google them if they like the music. This way, not only are you not stealing income from them, but you are actually helping promote their music. Now I realize that not every big artist is going to agree with me, but I would venture to guess that the majority of independents will.
Of course if it is a revenue generating project, then I would suggest contacting the artist to secure permission ahead of time, but even then only if it what I would consider a "permanent" type of product. In other words, if you are shooting video for a dive trip and selling 20-30 copies to the divers on that trip, yes that is revenue generating, but it's not permanent and it's not really as a result of the music. If, however, you are filming a movie, TV show, commercial, anything that is more permanent, then sure, the artist should get some kind of compensation.
Personally, I'm actually contacting underwater photographers and videographers requesting that they please use some of my music in their productions, in exchange for displaying credits and my website somewhere on the slideshow/video.
If you're interested, you can listen to my entire first album using the sitewide player on my website at
www.JustAScubaCowboy.com and if you purchase any tunes or already own them, please feel free to use them in any "home videos" that you would like, even if they get published out on the web. Again, I consider it an honor and encourage it! Heck, I would love to see a copy of any production that has one of my tunes in the background... how cool is that!?!?!