Delfonics lead singer William 'Poogie' Hart has died aged 77.

The founding member of the hugely influential and much-sampled soul band - whose 1968 hit ‘La-La (Means I Love You)’ was covered by Prince and the Jackson 5 - passed away from complications from surgery at Temple University Hospital in Philadelphia, where he was hospitalised with breathing difficulties, his son Hadi confirmed to TMZ.

William formed Delfonics with his brother Wilbert, Randy Cain, Ritchie Daniels and Thom Bell in 1965, and they are famous for popularising The Sound of Philadelphia.

Their hits include 'Didn't I (Blow Your Mind This Time)', 'Break Your Promise', 'I'm Sorry', and 'Ready or Not Here I Come (Can't Hide from Love)'.

'Didn't I (Blow Your Mind This Time)' landed them a Grammy for Best R'n'B Performance By A Duo Or Group, Vocal Or Instrumental in 1971.

'Ready or Not Here I Come (Can't Hide from Love)' was sampled by the Fugees on their 1996 hit 'Ready or Not' and Missy Elliott's 1997 track 'Sock It 2 Me'.

William penned all of their tunes with arranger and producer Thom.

The late Randy left the group in 1971 and was replaced by Major Harris before the group went their separate ways in 1975.

William continued to work with various incarnations of the line-up throughout the 90s and 2000s.

As well as legions of samples and covers, Delfonics' music was used in movie soundtracks and games.

'Didn't I' and 'La-La' were used in Quentin Tarantino's 'Jackie Brown', while 'Ready or Not Here I Come (Can't Hide from Love)' and 'Funny Feeling' feature in 'Grand Theft Auto V'.

Tributes have poured in for William.

KISS rocker Paul Stanley tweeted: "LOVE The Delfonics! They truly defined The Sound Of Philadelphia. William Hart not only sang but co-wrote their greatest hits with Thom Bell. I’d know that voice anywhere. Rest In Glory.”

New Kids on the Black, who covered 'Didn't I (Blow Your Mind This Time)' on their 1986 self-titled debut studio album, wrote: "We are so saddened to learn of the passing of William Hart, the lead singer and founding member of the Delfonics as well as the writer and singer of one of our most beloved songs: the cover version of “Didn’t I Blow Your Mind”. Rest In Peace. (sic)"