what instrument does the second type of person play?
Organ
Organist
An organist is a musician who plays any type of organ. An organist may play solo organ works, play with an ensemble or orchestra, or accompany one or more singers or instrumental soloists. 
who was olivier messiaen? He was a French composer, organist, and ornithologist
wiki:20829025
Organist [SEP] Introduction
An organist is a musician who plays any type of organ. An organist may play solo organ works, play with an ensemble or orchestra, or accompany one or more singers or instrumental soloists. In addition, an organist may accompany congregational hymn-singing and play liturgical music.