I discovered Yeasayer by accident: I was playing a radio station on last.fm when the song "Germs" popped up. I liked the track. A few songs later "Sunrise" played. I really liked that one. I then went on a bit of a rampage, downloading everything I could find by them. I completely missed this band back in 2007, so I'm making up for lost time now.
Yeasayer is a so-called "experimental band," whatever that means. Their music is a little trippy, a little psychedelic, and a little indie. Their first album, "All Hour Cymbals," was released in 2007 and their upcoming album is to be released January 2010, although they've been hinting that they'd do something "big" in October. Rumor has it they're incredible live. (An excellent live version of 2080 is shown above.)
Many of their songs are melancholic, with themes ranging from being left behind by evolution ("Sunrise": the fish began to fly / I went and stole some wings / and thought why can't I), homicide ("Wait for the Summer"), and the stunningly apocalyptic "2080", which features the lyric "in 2080 I'll surely be dead / so don't look ahead, ever look ahead."
In the midst of the melancholy, however, there is always a bit of hope to be found. In "2080" they end by suggesting that we join a commune, returning to the old days as we reject the "times we're living in." The final verses of "Red Cave" are downright cheerful, as Chris Keating expresses love for his family and friends. For that matter, while we may be in a graveyard in "Wait for the Wintertime," "we'll be making babies" nevertheless!
Let's face facts here: you already like Yeasayer, you just don't know it yet.