The Experience Music Project (EMP) Museum is at the end of the monorail ride from Westlake Center or a short cab ride from Belltown. Frank Gehry designed an amazing building to house a feast of pop culture and music memorabilia inside. The EMP Museum is dedicated to music and entertainment of the late 20th centurt. It has a number of regular installations plus revolving exhibits, in our case it was the 20th anniversary of the death of Curt Cobain with a special installation in the Museum chronicling the rise of grunge in general and Nirvana in particular. Hometown guitar god Jimi Hendrix was also featured with a fantastic exhibit outlining his career and showcasing his instruments and costumes. The exhibits change regularly- one on horror movies and science fiction in general was on when we were there but this is a fantastic space to walk around, both inside and out.
The gift shop deserved mention as it is a bazaar of the bizarre. You can find old band tour shirts, or full sized Doctor Who replicas. It is quite the scene.