Again, I'm late to a "I'm in Seattle" thread.
Tonight, Wire is playing Neumo's in Capitol Hill.
As far as nature stuff, it's a bit out of the way, but if you drive to 100th st. and Holman Rd., or take the 28 bus up there (make sure the bus says "Northgate" or "Broadview" if you do), there's a south entrance to Carkeek Park. It's right next to a QFC supermarket, so you can stock on water, trail mix, or what not. I happen to live right near there, and sometimes walk there during my lunch break on Thursdays, my work-at-home day. Anyway, it's a great escape from all the urban stuff, and you really feel like you escape when go inside it, even though you're right in the city. On the waterfront end of Carkeek Park is this tiny little beach looking out toward Bainbridge Island and, if not so cloudy, the Olympic Mountains.
But if you have a car, you might as well go to Discovery Park, which is west of Magnolia and Queen Anne Hill. There are tons of trails there, and the end has a really nice view of Puget Sound.
But if you're here Saturday ie Record Store Day, The Stranger has a great rundown of what's going on. If you want to meet Peter Buck or Duff McKagan, you're in luck:
http://lineout.thestranger.com/lineout/archives/2011/04/12/this-saturday-is-record-store-day