John Lawton was the vocalist for three years 1976 - 1979 and sang on three studio albums (plus one posthumous live album). Lawton can also be seen on a few Uriah Heep videos. The group had almost finished recording the fourth studio album when disagreements with the band leader Ken Hensley led to Lawton being fired.
In 1995 Lawton returned briefly to Heep for one tour after the current line-up's vocalist Bernie Shaw was recovering from throath operation. This was just a temporary arrangement and Lawton never meant to join the band permanently.
Recently Lawton has appeared as guest on a couple live albums.