The assets of UMI were bought by Steinway Musical Instruments in 2000 and in January 2003 were merged with other Steinway properties into a subsidiary called Conn-Selmer. The company was sold in 1980 and then again in 1985, reorganized under the parent corporation United Musical Instruments (UMI) in 1986. Conn was divested of its Elkhart production facilities in 1970, leaving remaining production in satellite facilities and contractor sources. In 1969 the company was sold in bankruptcy to the Crowell-Collier-MacMillan publishing company. During the 1950s the bulk of its sales revenue shifted to electric organs. Its early business was based primarily on brass instruments, which were manufactured in Elkhart, Indiana.

It bought the production facilities owned by Charles Gerard Conn, a major figure in early manufacture of brasswinds and saxophones in the USA. Conn Ltd., sometimes called Conn Instruments or commonly just Conn, is a former American manufacturer of musical instruments incorporated in 1915.

C g conn trumpet serial numbers