Uriah Heep's by-the-books progressive heavy metal made the British band one of the most popular hard rock groups of the early '70s. Formed by vocalist David Byron and guitarist Mick Box in the late '60s, the group went through an astonishing number of members over the next two decades -- nearly 30 different musicians pa**ed through the band over the years. Byron and Box were members of the mid-'60s rock band called the Stalkers; once that band broke up, the duo formed another group called Spice. Spice would eventually turn into Uriah Heep in the late '60s, once Ken Hensley (guitar, keyboards, vocals) and ba**ist Paul Newton joined the pair. Former Spice drummer Alex Napier was the band's drummer for a brief time; he was quickly replaced by Nigel Olsson. br /br /Uriah Heep released their debut album Very 'eavy...Very 'umble (called Uriah Heep in the U.S.) in 1970. After its release, Keith Baker became the group's drummer; he recorded Salisbury, the group's second album, before deciding he couldn't keep up with the band's extensive touring and was replaced by Ian Clarke. Salisbury, featuring a 16-minute title track recorded with a 26-piece orchestra, showcased the band's more progressive tendencies. Later that year, Ian Clarke was replaced by Lee Kerslake and Mark Clarke replaced Newton; Mark Clarke quickly left the band and Gary Thain became the group's ba**ist. This lineup of Uriah Heep was its most stable and popular; beginning with 1972's Demons and Wizards, they released five albums between 1972 and 1975. br /br /After 1975, the band's popularity began to slip. Byron left the band in 1977 and was replaced by John Lawton, yet the group's fortunes kept declining right into the early '80s. However, Uriah Heep soldiered on, continuing to release albums into the '90s and 2000s. The album roster included Different World (1994), Sea of Light (1995), Sonic Origami (1998), and Spellbinder (1999). ~ Stephen Thomas Erlewine, All Music Guide