Songfacts®:

• "Summersong" is a more mainstream sound for the indie-scene darling band The Decemberists. It was written by their frontman Colin Meloy. Some sharp observers have compared it to Eddie Brickell's "What I Am." There's certainly some similar instrumental and structural similarity between the two, but not really that close.
• While the song itself has no charting record, the album The Crane Wife was voted Best Album of 2006 by National Public Radio listeners. It was also The Decemberists highest-charting album at the time, clocking in at #35 on the Billboard Album 200, which shows a steady progress towards their next two albums at #14 and then #1.
  
  Critic Jim DeRogatis in the Chicago Sun-Times called this album "the best Jethro Tull album since Heavy Horses." He clarifies that he means that as a compliment. DeRogatis cites an interview in which it is revealed that keyboard and accordion player Jenny Conlee is in fact a big Jethro Tull fan.
• As you might expect, The Crane Wife is a concept album, one which revolves around a story based on a Japanese folk tale, and another inspired by Shakespeare's The Tempest. Did somebody say "progressive rock"?