[1] He studied the influence of folk music on some of Béla Bartók's works in Hungary in 1983, as well as composition with Attila Bozay and Zsolt Serei.

[4][5] Over the years Ritchie has collaborated with a number of writers such as Stuart Hoar, Keri Hulme and librettist Jeremy Commons.

[6] A further collaboration with Hoar produced Quartet (2004), a comic operetta examining the lives of classical musicians on tour in New Zealand.

[10] Ritchie set works by Dunedin poet Elena Poletti to create Lullabies (2015) which were originally commissioned and performed by the Auckland Choral society.

[12] 24 Preludes display many different musical influences: neo-Romantic composers, a range of time signatures, contrapuntal and harmonic styles, harpsichord and organ techniques, gamelan and celesta.

Ritchie was also trying out the use of the mathematical concept of the magic square also used by composers Peter Maxwell Davies and Gillian Whitehead.

[15] Ritchie received a Trust Fund award from the Composers Association of New Zealand in 1998 in recognition of his achievements in composition.