For instance, in "And the light shines in darkness", a massive dark-sounding layer with much rhythmical unrest is gradually introduced to a lighter-sounding chord with notes from the harmonic series.
Mostad has written chamber music, solo pieces for piano, guitar, organ and used electronics, both pre-recorded and live with interaction with live musicians, but his main focus has been orchestral and vocal music.
Music ranging from small chamber pieces to the multimedia show Terje Vigen based on texts by Henrik Ibsen and theatrical music for Ibsen's Peer Gynt were written for local ensembles in Fredrikstad.
Mostad has also had commissions from Ny Musikk [no], NRK radio and TV, Ungdomssymfonikerne [no], Det Norske Blåseensemble, Amsterdams Gitaartrio and Oslo Sinfonietta as well as from local ensembles in Fredrikstad.
His orchestral works "House", "The light shines in darkness" and "Concerto for cello and orchestra" were chosen by a jury of the Norwegian Society of Composers to be recorded on the Aurora label, resulting in the CD "The light shines in darkness" with Oslo Philharmonic, cellist Øystein Birkeland and conductor Michel Swierczewski.
An important inspiration during his studies were the seminars in sonology and on Gustav Mahler by Olav Anton Thommessen.