On Tuesday, upper school jazz band members attended an impromptu master class by pianist Dalton Ridenhour in the Patil Theater. A specialist in stride piano, the style that developed from ragtime, Ridenhour talked about the history of ragtime, which was influenced largely by classical and folk music, and its influence on jazz piano. Ragtime became popular with people who played the piano in their homes and purchased sheet music of ragtime pieces to perform for their families and friends. In New York City’s Harlem neighborhood, Ridenhour explained, residents would host “rent parties,” where musicians were hired to perform and attendees would pay admission in order to help tenants pay their rent. James P. Johnson, an early notable stride pianist, was a frequent performer at such parties. Ridenhour performed pieces by both Johnson and influential ragtime composer Scott Joplin to demonstrate both the differences and similarities between the two styles.