Petter Dass

A poet, as described by the Sixth Doctor, was "a marvellous, old Norwegian priest". He wrote "Nordlands Trompet". (AUDIO: Project: Lazarus)

Behind the scenes
Although the poet's name is not mentioned before the Doctor's interrupted by the sound of an explosion, the Doctor's description plus the lyrics of "Nordlands Trompet" positively identify him as Peter Dass.