A composite volume containing two treatises in Welsh on angling and musical theory, three lists of tune titles, and a large collection of tunes, compiled by John Thomas for the violin, some from printed sources and others written down from oral tradition. The tunes have been published, with related notes, in Cass Meurig (ed.), Alawon John Thomas: a fiddler's tune-book from eighteenth-century Wales (Aberystwyth, 2004).