Hayes has worked with Van Morrison, Jesse Colin Young, The Rowans, Terry & The Pirates, Southside Johnny and the Asbury Jukes, Country Joe McDonald and others.
The other Morrison albums Hayes has contributed to are Veedon Fleece (1974), Into the Music (1979), Common One (1980), Beautiful Vision (1982), Inarticulate Speech of the Heart (1983), Live at the Grand Opera House Belfast (1984), A Sense of Wonder (1985), No Guru, No Method, No Teacher (1986), Down the Road (2002), What's Wrong with This Picture?
Hayes and Parsons (formerly of The Byrds, Flying Burrito Brothers) met in sessions on the Mendocino Coast, where both live.
In 2013, the duo of Parsons and Hayes invited singer-songwriters Gwyneth Moreland, for whom Hayes had produced the album "Ceilings Floors and Open Doors" (2014), and Steven Bates, a long time California club headliner, to join them in four-part harmony vocals and a showcase for each member's songwriting.
Both Ceilings Floors and Open Doors and Cider won the two of them accolades including topping Folk singles and album Charts.