William Teasdale Armstrong, a well-known craftsman and former C.G. Conn shop foreman, established his tiny flute repair company in Elkhart, Indiana, in 1931. Word of his ability and unwavering commitment to quality spreadquickly, and he was soon asked to build instruments for professional musicians. 

Edward Armstrong, who apprenticed under his father and shared his father's attention to detail about quality, inherited the great Armstrong heritage. Edward's attention to detail extended far beyond the creation of professional-level instruments. He saw the necessity to provide high-quality instruments to an ever-increasing number of students and community musicians.Armstrong collaborated with Albert Cooper in the 1970s to create a "new" flute scale. Prior to the introduction of this new scale, flute producers would adjust the common A=435 tuning by cutting the end of the head joint to raise the pitch to A=440. While this helped to fix the pitch in the center registers, it had little effect on the other octaves. Armstrong and Cooper worked to develop a completely new flute with better performance. A tapered head joint, as well as changes to the dimension and arrangement of tone holes, would be among the modifications. The 102, 103, and 104 model flute platforms were based on this revised flute.

The Armstrong woodwind company was sold to King Musical Instruments in 1984, and the two companies ultimately amalgamated to establish United Musical Instruments in 1985. (UMI). In 2002, UMI joined with the Selmer Company to form Conn-Selmer, Inc.