He has been compared to many of his influences including Nick Drake, Leonard Cohen and Bert Jansch while critics also note his has own distinctive voice both vocally and in his songwriting.
"...a bloke who has the gift of song well at his fingertips and his observational tales of life and love lost come straight from the heart and soul without the usual fancy detours........." All Whats Rock
"John Cathal O’Brien’s “Acid Week” is certainly a wonderful surprise. With an overabundance of “folk pop” and “indie folk” artists out there, it’s refreshing to hear a folk artist with something to say lyrically" Music Perk
"John Cathal O’Brien brings a new feel to a classic genre. Lush with addicting guitar progressions, an honest and edgy vocal style, and a dream like atmosphere, the record boasts the aesthetic of indie folk anthems. Though the songs are diverse from one another, there is a glue that holds them all together much like a concept album. Most importantly, the EP never loses sight of the emotional platform great songs are built from."
- Joe Cosini, RRPR