The Millennium Jazz Orchestra is a jazz orchestra consisting of professional Dutch, German, and English musicians under leadership by Joan Reinders, since 1985. The MJO strives for innovation and innovative compositions for big band and therefore almost exclusively performs its own compositions and/or arrangements by Joan Reinders and MJO members.

A selection from the long list of guest soloists with whom the band has played, includes:
Benny Golson, Kenny Wheeler, Toots Thielemans, New York Voices, Eric Vloeimans, The Four Freshmen, Conrad Herwig, Jiggs Whigham, Bob Malach, Philip Catherine, Dick Oatts, Gary Smulyan, Jasper van ’t Hof, Ack van Rooyen, and many more.

The MJO has performed on various major stages, including the North Sea Jazz Festival, TivoliVredenburg, Bimhuis, and the Concertgebouw.

In 2006, the orchestra was invited, together with singer Fay Claassen, to give a concert at the International Association of Jazz Education congress in New York (USA).

The orchestra has since recorded thirteen CDs.

In honor of the 40 year anniversary, a digital double album, Chronology Vol 1 & Vol 2, was released.

The latest album, Concertos, was released in 2025 and contains two different orchestral works: ‘Concerto for Trombone and Jazz Orchestra’, featuring the renowned trombonist Mark Nightingale (UK), and ‘Concerto for Jazz Orchestra’, with MJO soloists.

The CD Both Sides Now, featuring singer Marjorie Barnes, was released in May 2023 and received an Edison nomination.

‘The Netherlands, with a population less than that of New York State, is home to no less than four of the world’s most accomplished jazz ensembles—the Metropole Orchestra, the Jazz Orchestra of the Concertgebouw, the Ebony Big Band and the Millennium Jazz Orchestra whose latest album, Lookin’ East, does nothing to subvert its status as a member of the Big Four. Indeed, there is ample cause to argue that the MJO belongs at the very top of that plateau, steep as it may be.’
Jack Bowers – allaboutjazz.com (Lookin’ East)