Strictly speaking, this CD isn't all 20s music, but it's a great compilation nonetheless: Fascinating Gershwin, available at Starbucks (or at least, available at the Starbucks I was at yesterday -- I don't know about all of them).
It was the packaging that caught my eye initially, as it looks extremely Art Deco:
And of course as soon as I noticed the names on the sticker, I was sold.
It's a great CD, a little different than much of my other 20s music, which is good. A lot of the music in this album actually seems to date from the 1950s or so, but it's still good for setting a 1920s mood. There is a handy little booklet that gives a brief history of each track, as well as a short bio about the Gershwin brothers.
Definitely a good CD, not to mention a rather attractive case (if you care about such things -- which I do), if you happen to see it at your local Starbucks!