​Riggen counts the main components in his musical career as the ensembles he has founded, co-founded, or conducted.
These include conventional jazz quintets (Matt Riggen Quintet), chordless projects built specifically to play free jazz (OGC), and large-ensemble social protest groups (Liberation Music Collective, Marquette Park Composer's Workshop).
His ability to put the right personnel into the same room to make a specific project work is consistently evident
(for example, as with Ouija Board, nights of improvisers thrown into completely new groups curated by Riggen at Slate Arts).
​ Riggen's ability to draw energy out of and spur on his ensembles makes them stronger than the sum of their parts, and his intensity is rewarded with his ensembles responding in kind.
Such ability has also led to invitations to guest conduct other large ensembles, such as the Sean Imboden Large Ensemble of Indianapolis.
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As of October 2017, Riggen is now the Director of Music at Marquette Park in Chicago.
He works in the historic neighborhood's Cultural Center to provide private and group-class musical instruction to its residents, organize recitals of his students,
​and put on large-ensemble performances of repertoire from Marquette Park's musical library (compiled over the past 70 years).
His role lies somewhere between artist-in-residence, band director, repairman, facilitator, and adjunct lecturer.
As the Director, he currently teaches beginning-to-intermediate lessons on the clarinet family,
​the saxophones, trumpet, trombone, baritone, tuba, piano, guitar, bass guitar, upright bass, and drumset.
Two Marquette Park groups whose rehearsals Riggen facilitates regularly tour within Chicago:
the Marquette Park Composer's Workshop and the student-based Marquette Park Quartet/Sextet, which performs at cultural centers around the city and festivals like Fiesta Del Sol.
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From August 2021 to July 2025, Riggen served as the Director of Jazz at Baker College Prep.
Employed by Jazz Empowers to head up this South Side charter school's band program, Riggen's role here was closer to that of a traditional band director.
Responsible for teaching students musical excellence from their very first note, Riggen has been able to produced a competitive jazz program
honored internally within the Noble Charter School Network in less than 3 years,
and was able to get students performing in the Noble Honor Band and send ensembles to the Noble 25 Gala at the Field Museum.

Performing with alto saxophonist Jafet C. at Marquette Park Listening Party, Spring '18

"Jazz Riffs and Short Scripts" w/ Baker College Prep, Winter 2022

Helping deep-listening artist Anna Wolfe-Pauly with an exercise derived from Pauline Oliveros' work in a workshop for students & parents, Fall '18

Marquette Park Sextet at Fiesta Del Sol, Summer 2024

Conducting the Chamber Ensemble of Marquette Park, Fall '19

Inaugurating the Anchor Structure at Marquette Park with curator Carlos Flores, Fall 2024

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