Musician, composer, pharmacist, and teacher Thomas Henderson Kerr Sr. was born May 7, 1888, in Cambridge, Maryland, the eleventh of the twelve children of Charles H. Kerr and Mary Jane Lloyd Kerr. His father, a brass player and teacher who organized the Merry Concert band in Cambridge, Maryland, worked at the U.S. Government Printing Office in Washington. Charles H. Kerr's father, Edward Kerr, was a singer of spirituals during the Civil War.

Thomas Henderson Kerr Sr. lived the first six years of his life in Cambridge, on Maryland's Eastern Shore. George Owens, a Baltimore violinist, visited the Kerr household and expressed interest in teaching young Thomas violin. When the Kerr family moved to Baltimore in 1904, Thomas attended Waesche Street School, where he would study with Owens. He became so proficient at the violin, he was engaged to play at church functions. After mastering violin, he taught himself piano and flute. He was adept at sight-reading, music theory, harmony, and composition.

Kerr Sr. graduated in 1909 from what was then called the Colored High School and Training School. In high school he formed his own society orchestra made up of six to eight musicians.

In the 1910s the orchestra performed regularly at the Galilean Fisherman's Hall and at Brown's Grove aboard the Starlight Steamer. The orchestra specialized in the latest dance music on Broadway. Kerr obtained material for his orchestra from touring orchestras performing at Ford's Theatre. Sitting in the balcony at Ford's Theatre with a pile of music manuscript paper, he would transcribe the melodies of the latest showtunes. The next night the orchestra would perform Kerr's arrangements. Kerr's career as a musician helped him finance his studies at the Howard University School of Pharmacy and open his own drugstore. He passed the State Board Examination before graduating in 1912 and opened Kerr's Drug Store in Baltimore City at 723 George Street on July 19, 1919.

Kerr's compositions range from ragtime to orchestral preludes. In 1911 the Equitable Music Company of Baltimore published Kerr's "That Hobble Rag," inspired by the hobble skirts worn by fashionable ladies at ballroom dancing classes and socials. Kerr's unpublished works, including the orchestral preludes Dyanza, Day Dream, Genee, and At Evening, were performed at Douglass High School commencement exercises by ensembles led by William Llewellyn Wilson. Kerr collaborated with Wilson and lyricist Kennard Williams, writing and producing their own musical shows at Galilean Fisherman's Hall in the 1920s.

Thomas H. Kerr Jr., a piano instructor at Howard University, observed that his father was the best sight-reader (at piano, flute or violin) he had ever known. At home he would read through an entire collection of “Old World Favorites,” ending with a speedy rendition of Scott Joplin's Maple Leaf Rag. His sight-reading ability amazed members of the Peabody Conservatory faculty, who found it difficult to believe that Kerr was self-taught. After Kerr Sr.'s retirement in 1960, he intended to fulfill a lifelong ambition to study violin and flute Peabody. While sight-reading for placement, Kerr demonstrated such unusual ability that the faculty member hearing the examination called his colleagues to witness Kerr's remarkable abilities.