- Donny Osmond
- Sarah Àlainn
- Shulem
- Jimmy Somerville
- Carolina Deslandes
- Andreea Banica
- Anjani Thomas
- Skott
- Luciano Pavarotti
- Norah Jones
- Judy Garland
- Jonathan Antoine
- Arielle Dombasle
- Chenoa
- Emma Blackery
- The Puppini Sisters
- Tones And I
- Aled Jones
- Theuns Jordaan
- Natasha Marsh
- Vittorio Grigolo
- Magalie
- Polina Gagarina
- Sean Smith
- Mark Vincent
- Charlotte Jane
- Kindred Spirits
- Céline Dion
- Human Nature
- Rita Wilson
- Rhydian
- Ren
- Katrina (Katrina and the Waves)
- The Manhattan Transfer
- Kristin Chenoweth
- Lesley Garrett
- Andreya Triana
- AURORA
- Andrew Cushin
- Josh Groban
- Beau Dermott
- Natalie Cole
- David Warin Solomons
- Harry Connick, Jr.
- Lewisham And Greenwich NHS Choir
- k.d. lang
- ERA
- CRBL
- Tony Bennett
- Katherine Jenkins
- Alfie Boe
- Il Divo
- Beth Rowley
- Ada Ehi
- Kristian Kostov
- Unsung Lilly
- Si Cranstoun
- Nat "King" Cole
- Patrizio Buanne
- Andrea Bocelli
- Matt Dusk
- Maddi Jane
- Sixpence None the Richer
- Diana Krall
- Kimberley Walsh
- DCappella
- Meaghan Smith
- Will Martin
- All Angels
- Bobby McFerrin
- Pat Boone
- Gino Vannelli
- G Flip
- RyanDan
- Mary Zilba
- Madeleine Peyroux
- The Kenyan Boys Choir
- Frank Sinatra
- Ray Quinn
- Vadé
- Al Martino
- Michael Ball
- Mutya Buena
- Dima Bilan
- Only Men Aloud!
- Michael Bublé
- Blake
- Liza Minnelli
- Lizz Wright
- Ben Earle
- Bryn Terfel
- Peter Hollens
- Inju5tice
- Liv Dawson
- G4
- The Black Mamba
- Phil Gould
- Shirley Bassey
- The Rat Pack