His work Mostraspelet – a historic play depicting the Christianization of Norway – has seen annual performances in Bømlo since 1983.
As a composer, Habbestad debuted with a first prize for his choir work Magnificat in TONO’s 1978 composition competition.
Examples of this focus include oratories and liturgical dramas such as Ubal, Jabal, Kar og kjerring, Noahs draum, and Angeli, 18 englebilder.
Major choir works in Habbestad’s list of works includes 3 Cantica (Magnificat, Nunc Dimittis and Benedictus Dominus) , Nox Praecessit, Stabat Mater dolorosa for male vocal quartet and men’s choir, Ego Clamavi, Apal, Kverni and Sju vindar.
[4] Habbestad served as a member of the board for the Norwegian Society of Composers from 1987 to 1996, as deputy director for the organization from 1990 to 1996 and as leader of NSC’s advisory committee from 1996 to 2002.