"From that moment in the summer of 1970 when we set off on our musical odyssey the world opened up and the roller coaster ride started", he said.
"Little Willy" was released in the U.S.in September 1972 and ranked as one of 1973's biggest hits.
Priest was born in Hayes, England, and - like many musicians of his era - was influenced by The Shadows before becoming enamoured by the Rolling Stones and The Who.
The news was confirmed by fellow Sweet member Andy Scott. "The noise we made as a band was so powerful", Scott continued. The band scored smash singles with "Co-Co", "Wig Wam Bam", the chart-topping "Blockbuster", "Hellraiser" and "Little Willy", The latter would become the quartet's first US hit, reaching No. 3 in early 1973.
Priest had been living in the Los Angeles area for several years, and his band played often at local venues including the Canyon clubs in Agoura Hills and Santa Clarita. The band consisted of lead vocalist Brian Connolly, drummer Mick Tucker, guitarist Scott and bass player Priest.
Sweet parted ways with Chinn and Chapman in 1974, determined to write their own material.
Other Top 10 hits included Fox on the Run (fifth in 1975), and Love is Like Oxygen (eighth in 1978).
After tributes flooded in to remember Steve, the band took to social media to thank their fans for their kind messages of support through such a hard time as well as their longterm loyalty. After Connolly's departure in 1979, Sweet carried on as a three-piece outfit for three more albums before disbanding in 1981.
"When Sweet were on [TV] you sat there in awe thinking, 'sod the school careers adviser that's the job for me, '" wrote The Damned's guitarist Captain Sensible.
David Ellefson of Megadeth said that Priest was "without parallel".
"RIP Steve Priest", wrote Nancy Wilson of the USA rock band Heart. While an exact cause of death is not immediately clear, Priest was 72.
Priest is survived by his spouse, music publicist Maureen O'Connor, three daughters, Lisa, Danielle and Maggie and three grandchildren, Jordan, Jade & Hazel.