Le Guidon du plain-chant... par Jacques Doublet
A 1649 French plainchant guide by Jacques Doublet, published by G. Doublet, written to teach church singers the chant tones and their melodic formulas. The pictures are small woodcut-style musical staves with square notes and Latin or French captions, plus a bishop's coat of arms with a mitre, crosier and tasselled hat, all useful for historic typography and heraldry references.
