The Scottish Music Index
"The Index contains a Bibliography of over 200 volumes of Scottish instrumental music - mostly dance music but with many beautiful slow airs - published between 1700 and 1922 and an A-Z list of the tune titles in them (over 12000). The song books (with words) of central Scotland are not included, with one or two exceptions, like James Johnson's ever-popular "Scots Musical Museum" (1771) many of the songs airs in which are closely linked with dance; London-printed dance manuals are selected on the scale of their Scottish content; the Gaelic song repertoire and the military pipe manuals are fully listed online elsewhere. The Index features Source Codes (where the tune can be found), Key and Time Signatures and a Theme Code listing for cross-referencing entries...
Membership of the Scottish Music Index costs £10.00 and lasts for 24 months."