The book and albums explore the field of what Chusid coined as "outsider music".

Chusid's work has brought the music of several leading performers in the outsider genre to wider attention.

These include Daniel Johnston, Joe Meek, Jandek and Wesley Willis.

Notable amongst these are nursing home resident Jack Mudurian who sings snatches of several dozen songs in a garbled collection known as Downloading the Repertoire and the obscure and extreme scat singer Shooby Taylor AKA 'The Human Horn.'

Songs in the Key of Z – The Curious Universe of Outsider Music, the companion compilation albums to Chusid's book were released on Which?

The collections, compiled by Irwin Chusid, include performances by gay country singer Peter Grudzien, music schoolteacher B. J. Snowden, and Swedish Elvis-impersonator Eilert Pilarm, along with better-known artists such as Daniel Johnston, the Shaggs, Wesley Willis, Joe Meek, and Captain Beefheart.

"Stout-hearted Men" – Shooby Taylor, The Human Horn 7.

"Virgin Child of the Universe" – Song poem, Unknown 10.

"Cousin Mosquito #1" – Congress-Woman Malinda Jackson Parker 14.

"Standing in a Trash Can (Thinking About You)" – Legendary Stardust Cowboy 16.

"Vampire Suite" – Captain Beefheart & His Magic Band 17.

"Baby, Your Love's in Town" – "Dusty Roads" Rowe 20.

"True Love" – Tiny Tim With Miss Sue 1.

"Adele's Laughing Song" - Florence Foster Jenkins 17.

"Hi, Dear Mister Master Keith Richards (Intro)" - Paul "Super Apple" 22.

"Please Call, Keith (Outro)" - Paul "Super Apple" 1.

"Star's Ghost" - Frances Cannon, The Singing Psychic 3.

"Dock of the Bay" - Mexia State School Sunshine Singers 7.

"Hey Fireman, Put out the Fire" - Omo the Hobo 16.

"Letter to a Christian" - Hallmark Song-Poems & Alice J. Jackson 18.