- 1936—Alexander Harley and his wife Frances founded the Maine Music Masters at Maine Township High School in Park Ridge, IL.
- 1952—Maine Music Masters became incorporated and was renamed Modern Music Masters.
- 1954—The first individual member recognition, known as the Top-Notcher Certificate of Achievement, was presented. This certificate was renamed Tri-M® Leadership in 2002.
- 1971—First Master Musician Certificate was presented.
- 1983—Modern Music Masters became a program of MENC: The National Association for Music Education and was officially renamed the Tri-M Music Honor Society.
- 1986—The first year Tri-M was recognized by the National Association of Secondary School Principals (NASSP) as an approved program.
- 1989—The first State Conference Achievement Recognition was presented to Tri-M members accepted to All-State Honor Ensembles. This certificate was renamed Honor Ensemble Achievement in 2003.
- 2002—State Chapter of the Year recognition was given in addition to the National Chapter of the Year.
- 2002—The Top-Notcher Recognition was renamed Tri-M Leadership.
- 2003—The State Conference Achievement Recognition was renamed Honor Ensemble Achievement and was expanded to recognize Tri-M member participation in state, division, and national honor ensembles.
- 2003—The first Tri-M Outstanding Service Recognition was presented.
- 2004—The first Tri-M Alumni Achievement Recognition was presented.