William Lawrence Mitchell was an American trumpeter, bandleader, soul, R&B, rock and roll, pop and funkrecord producer and arranger who ran Royal Studios in Memphis, Tennessee. He was best known for his Hi Records label of the 1970s, which released albums by a large stable of popular Memphis soul artists, including Mitchell himself, Al Green, O. V. Wright, Syl Johnson, Ann Peebles and Quiet Elegance.
Known at the recording studio as "Papa Willie", Mitchell earned his nickname by taking over the reins of Hi Records in 1970 and guiding it through its most successful period. Mitchell's productions have been much noted for featuring a hard-hitting bass drum sound (usually played by pioneering Memphis drummer Al Jackson, Jr. of Booker T. & the M.G.'s).
A trumpeter and bandleader in his own right, Mitchell released a number of popular singles for Hi Records as an artist in the 1960s, including "Soul Serenade." It peaked at number 43 in the UK Singles Chart in April 1968.
Through the 1980s Mitchell ran his own independent record label, Waylo Records. Acts on the label included Billy Always and Lynn White.
In 1987, Joyce Cobb recorded several singles for Waylo, one of which made it to No. 3 on the British R&B chart: "Another Lonely Night (Without You)", while in 1987 Mitchell worked on a version of Wet Wet Wet's debut album, which was issued in 1988 as The Memphis Sessions.
He and Al Green revived their successful recording partnership in 2003 when Green recorded I Can't Stop, his first collaboration with Mitchell since 1985's He is the Light. Their 2005 follow-up project was Everything's OK.
Mitchell died in Memphis on January 5, 2010, from a cardiac arrest.
His final work was producing the final Solomon Burke studio album, Nothing's Impossible, released in June 2010.