OK, here's a quick stab at a list of performers etc. from my notes - corrections/additions welcome:

Episode 1: "The Wild Rovers"
Interviews: Bono; Pete Seeger; Luka Bloom (song);
Rita & Sara Keane: song (A Stor Mo Chroi)
The Clancy Brothers: song (The Holy Ground)
Mick Moloney
The Everly Brothers: song (Rose Connolly)
Jean Ritchie; Tony McMahon; Sarah ???; Liam O Maonlai
Hothouse Flowers: song - excerpt (The Lakes of Ponchartrain)
Christy Moore & Donal Lunny: song (Christmas Day)
The Pogues
Barney McKenna & John Sheehan
Bono + U2: song (My Wild Irish Rose)

Episode 2: "No Frontiers"
Pete Seeger; Tommy Makem; Jean Ritchie; Sarah Makem
Liam Clancy: song (The Patriot Game)
Brian Kennedy(?) - sound only
Davy Hammond; Christy Moore; Bono; Luka Bloom; Paul Brady
Paul Brady & Donal Lunny: song (Nothing But the Same Old Story)
Mary Bergin: slow air on whistle
Michael O'Suilleabhain: tune on Piano (The Fair Haired Child)
John Prine & friends: song (Paradise)
Emmylou Harris, Mary Black & Dolores Keene: song (Sonny)
Richard Thompson, Mary Black + friends: song (Waltzing's for Dreamers)
Mary Black + band: song (excerpt only) (No Frontiers)
Mick Moloney
Kilkelly (band): song (Kilkelly)

Episode 3: "The Strain of the Dance"
Michael O'Suilleabhain
Ricky Skaggs, Paddy Glackin & Mark O'Connor: tune(s) (Blackberry Blossom ++)
John & Paddy Killouri
Gussy Mahon (dancer)
Noel Hill + dance musicians
Jackie Daly & Johnny McDonough: tunes (polkas)
Mick Moloney
Frankie Gavin, James Morrison (archive recording)
Eileen Ivers + band: tube (Cherish The Ladies)
Frankie Gavin & Yehudi Menuhin
Frankie Gavin & Alec Finn, Colm Murphy: tunes (reels)
Irish session musicians
Michael O'Suilleabhain
Mary Custy, Sharon Shannon, Eoin O'Neill: tunes (?)
London session musicians incl. Roger Sherlock, Bobby Casey
Steve Cooney & ??? (tunes)

Episode 4: "The Light of Other Days"
Maire Na Chathasaigh: tune (Carolan's Farewell to Music)
Uileann pipers - Liam O'Flynn, Seamus Ennis
Sean O'Riada feature inc, Peader O'Riada, Ciaran Mac Mathuna _ others
Arty McGlyn & Nollaig Casey: tune (Moran's Return)
John Cage incl. avant gard composation (Roratorio)
Glenstal Abbey Monks
Michael O'Suilleabhain: experimental music

Episode 5: "The Parting Glass"
Donal Lunny + band
Maura O'Connell
De Danann + gospel group: song (Hard Tines Come Again No More)
Elvis Costello & Mary Coughlan: song (The Mischievous Ghost)
Everly Brothers & Liam O'Flynn: song (Darling Don't Let Our Love Die)
Emmylou Harris & Liam O'Flynn, Davy Spillane: song (fragment only)
Davy Spillane Band: tune (Equinox)
The Waterboys: songs (The Stolen Child, fragment only; Song For the Life)
Tony McMahon: tune (The Music of the Ghosts)
Martin O'Connor & Donal Lunny: tune (reel)
Pierce Turner: song
Mary Coughlan & An Emotional Fish: song
Michael O'Suilleabhain: tunes (second with orchestra)
The Voice Squad: song (The Parting Glass)