Though mostly self-taught, he sang in the choir and accepted a position as organist at the Methodist Church in Columbia, Pennsylvania.

B. C. Unseld taught at the New England Conservatory of Music in Boston, Massachusetts, and was the school's first secretary.

Later he taught at Fisk University in Nashville, Tennessee, and was the first principal of the Virginia Normal School of Music.

Unseld and Seward, with Biglow and Main publishers, imported John Curwen's Tonic Sol-fa method of shape note music and promoted it.

In 1911, Unseld moved to Lawrenceburg, Tennessee, to serve as dean of the new James D. Vaughan School of Music, one part of that famed entrepreneur's publishing enterprise.