You may not know the name John Byrne, but you will have certainly seen his art work on the covers of albums by artists as diverse as The Beatles, The Humblebums, Stealer’s Wheel, Donovan, Gerry Rafferty and Billy Connolly. Byrne is a Scottish artist and playwright, born in Paisley in 1940. He is the author of the multi-award wining TV series Tutti Frutti, which starred Robbie Coltrane and Emma Thompson, and Your Cheatin’ Heart, starring Tilda Swinton (to whom he is married). For the theater…