Haskell School of Music is a textbook about Euterpea and working with music in Haskell. It was originally started by Paul Hudak and was later finished by Donya Quick. The textbook contains many examples of using the Euterpea library and also graphical widgets for creating musical user interfaces (MUIs). The source code for these is contained in the HSoM library. For information on installing and using HSoM, please see the Euterpea setup page.
Update (13-Dec-2016): the textbook is currently scheduled for publication in 2017. (see most recent update below)
Update (27-Oct-2016): an out-dated, illegally posted version of the text was recently discovered for sale as a kindle version on Amazon, having apparently been posted by someone other than the authors. Online PDFs of old versions of the text are have been removed on this and other sites to prevent this from happening again while the formal publication process is underway for the correct, updated version. If you need access to older versions of the textbook for educational purposes while publication of the new version is pending, please contact Donya Quick by e-mail at email@example.com. Clarification: “educational purposes” means involved in a classroom somehow (in other words, instructors who are relying on the text to teach courses).
Update (27-Dec-2017): final versions were submitted a couple of months ago and the text is currently having formatting and design work sorts of things done by the publisher. This will probably mean an early 2018 release since, of course, there’s little of 2017 left.