Paul Hardy's Session Tunebook

Another Tunebook which provides lots of chords for accompanyment is made by Paul Hardy. He made it for Accordion-players, but it is useful for other instruments too.
http://www.pghardy.net/concertina/tunebooks/pgh_session_tunebook.pdf

Paul provides some more tunebooks (a set tunebook, a basic tunebook, a annex tunebook with tunes which will appear in a later version of his tunebook etc.) on his site, look at:
http://www.pghardy.net/concertina/tunebooks/