While I appreciate Julia's mention of James Johnson's "Scots Musical Museum" (6 vols, each of at least 100 songs, 1787-1803, Vols II-V effectively edited by RB himself), I very much think she's conflating TWO different collections of Scots music and song. It was surely
George Thomson's "Select Collection of Original Scotish Airs" which presented music, with "introductory and concluding symphonies" by the likes of Bishop, Haydn, Pleyel and Beethoven, for "people of condition"; each half-volume contained 25 songs, and RB did agree to contribute, stipulating that his verses were to be "above, or below, price". That is, he wouldn't write FOR money (tho', of course, he did make a bit of cash from selling his own collections of Poems- AFTER they had been written from "the impulse, not the wish").

Thomson's "Select Collection" was a magnificent Quarto, the sheet-music engraved on large copper-plates as was typical of collections WITH MUSIC at the time; Johnson's was unusual in that he had developed a method of simply striking the staves and notes on Pewter. It was, accordingly, much cheaper, and, like the many collections with words only (after all, the airs were familiar to everyone, and the majority of people didn't require a harpsichord accompaniment with thorough-bass for the violoncello), was well within the reach of what RB called "my compeers, the Common People".

Burns only saw one 1/2 Volume of the Select Collection; when Thomson sent him one (ONE!!!) copy, he also enclosed a £5 note. Burns was indignant - "you truly hurt me with your pecuniary package" - and swore that if GT ever attempted anything of the nature again then their correspondence was at an end. Quite apart from the subversion of RB's original statement re "priceless", what would it look like if he were concurrently writing for Thomson, for money, but sending words and indeed collected melodies to Johnson free of any charge? (Burns could write music, presumably after working out the melody on his fiddle and then transcribing the notes; two manuscripts are known). Fortunately, Thomson learnt sense, and confined himself to occasional gifts like a Paisley-pattern shawl for Jean. Burns continued to write to Thomson, and his letters include some of his own most valuable observations on the craft of song-making, together with some anecdotal material concerning some of those he made and/or collected.