What's Jewish about the jam band Phish? Many things, according to a new book.

(JTA) - Those who are Jewish or Phish fans - or both - have likely noticed at one point: Jews really seem to love Phish.

There are many possible reasons for this, starting with the fact that the genre-bending jam band has many ardent fans of all stripes, having sold millions of albums and played to enormous festival crowds for decades. Two of the band members - bassist Mike Gordon and drummer Jon Fishman - are also Jewish, and the group has been known to play Jewish songs such as "Yerushalayim Shel Zahav" and "Avinu Malkeinu" live.

But there's something else - a certain kind of spiritual aspec...