John Playford’s The English Dancing Master, or Plaine and easie Rules for the Dancing of Country Dances, with the Tune to each Dance was the first collection of country dance tunes published in the British Isles. The book was a huge success and ran to eighteen editions from 1651 until 1728. The word "English" in the title was probably meant as a dig at those who thought that the only worthwhile dancing master was a French one; it was dropped after the first edition.
Each subsequent edition introduced new tunes that had become popular while dropping others and consisted of traditional dance melodies and song tunes as well music from popular plays of the time. One example of the latter is Hole in the Wall, which appeared in the incidental music by Henry Purcell to the play Abdelazar, or the Moor’s Revenge.
An example of a tune being recycled over time is The Twenty-Ninth of May which may well have been in existence earlier than the 17th century. In the 1660s it was associated with a song which celebrated the restoration of the monarchy under Charles II on May 29th 1660 before appearing as a dance tune in the 1686 edition of The Dancing Master. Much later, in 1915, it was arranged by Martin Shaw as a hymn tune to the words All Things Bright and Beautiful.
Northumbrian pipers with the usual F Chanter know that the sound they produce is not the sound of the written note but the note one tone below. For guitar chords this is taken care of in the books as there is a separate series of chord symbols in the sounding key of the music.
However, if you are playing duets with a player of a non-transposing instrument you usually have to write all of the music out in the necessary key. Non-transposing instruments include violin, flute, recorder, etc.
The problem is solved in the "transposed inserts" - they contain exactly the same material as the main book but transposed down one tone. They are cheaper than the main books as they come without a card cover.