You could get lost for weeks in this 20-CD compilation of traditional music from Ireland, Scotland, Wales and indeed England, with rare recordings going back to 1908 and a singing 75-year-old Lincolnshire bailiff. It's mostly song-based, with a theme for each CD (courting, sea-faring, exile, politics, poaching, working, the drink, etc), and 20 fat little booklets for background.

Compiled by Dr Reg Hall of Sussex University, it sees the Irish represented by Sean Mac Donnchadha, Willie Clancy (singing Erin's Lovely Lee), Paddy Tunney, Micho Russell, Joe Heaney, as Bearla), Seamus Tansey's flute, Michael Coleman's fiddle (1921) and many lesser-known song sources like Mary Deaney, the Tipperary traveller who, though blind from birth, sang at fairs and reared 16 children.

The English singing is tinged with music-hall, with less natural ornament than the Irish or Scots, and characters like Harry Cox fetching up Gavin Bryars's Jesus' Blood Never Failed Me. But the north of England dance music is very Celtic, with old shepherds playing Northumbrian small-pipes, fiddles, mouth organs, melodeons and piccolos. The oft-slagged Morris tradition may be dominated by blunt polkas and reels - or heys, as they call them - but there's also Jinky Wells singing with his fiddle in 1936; Percy Brown playing the Cork Hornpipe (however it got to Norfolk), and Bob Cann's ferocious melodeon.

It's an astonishing repository. You can buy the CDs singly or the whole shebang will set you back a couple of ton, and a new shelf to go with it.