Beginning to Read Music for Traditional Musicians by Sarah Northcott.

Sarah Northcott writes: "I wrote this book because I couldn't find one to recommend to my adult students which wasn't either full of jargon from the start, based on classical music theory exams or aimed at children. This book covers the basic concepts of reading music and music theory. In simple, jargon-free language and diagrams, it explains:

the notes we play
how the notes are written
the length of the notes
bars and time signatures
reading rhythms
which notes to play - scales and keys
other symbols on the page

It also encourages students to use written music as a starting point only, and has suggestions for moving beyond the basic tune and adding all the extras which make a tune come alive. The book is based on western European traditional music and its close relatives in North America.