Richard Robinson's Tunebook
An excellent online collection of (mainly traditional) tunes: http://richardrobinson.tunebook.org.uk
In particular the site hosts copies of Aird's A Selection of Scotch, English, Irish, and Foreign Airs, adapted for the Fife, Violin or German Flute; printed and sold by I.A. Aird, Glasgow (circa 1780) and a collection of manuscripts kept by the Winder family, of Dolphinhome, Wyresdale, Lancashire (said to date from 1789, 1823, and 1835-41).