Sigma Alpha Iota was founded June 12, 1903, at the University of Michigan School of Music, Ann Arbor, Michigan. The Founders were seven upperclass and graduate students -- Elizabeth Campbell, Francis Caspari, Minnie Davis Sherrill, Leila Farlin Laughlin, Nora Crane Hunt,Georgina Potts, and Mary Storrs Andersen, all deceased.

The founding is described in a brief "History of Sigma Alpha Iota" by Elizabeth Campbell in the Pan Pipes of April, 1910: ". . .when seven gifted young musicians solemnly pledged themselves to help each other with sisterly affection, stand for the highest possible musical scholarship, for nobility and uprightness of character, and for the maintainance of friendly and unselfish relations among women in the musical profession."

Incorporation papers, under the laws of the State of Michigan, were signed December 1, 1904, and recorded December 15, 1904.

The first extension as a national fraternity came when requests from student groups brought the installation of Beta Chapter (Northern University, Evanston, IL; December, 1904), Gamma Chapter (American Conservatory, Chicago, IL; November, 1904), and Delta Chapter (Detriot Conservatory, Detriot, MI; March, 1907).

As extention continued, the first twenty-four chapters were named for the letters of the Greek alphabet in order. For the 25th to 48th chapters, "Sigma" was prefixed to the Greek alphabet in order.  This was continued for the 49th to 72nd chapters, with "Alpha" prefixed to the Greek alphabet. These have been followed with "Iota," and then "Beta," "Gamma," "Delta," "Epsilon," "Zeta," "Eta," and "Theta," prefixed to the Greek alphabet.