James Earl Jones | Prince Edward, Earl of Wessex | Louis Mountbatten, 1st Earl Mountbatten of Burma | Herbert Kitchener, 1st Earl Kitchener | Earl | Frederick Roberts, 1st Earl Roberts | Earl of Derby | Earl Warren | Earl of Pembroke | Robert Harley, 1st Earl of Oxford and Earl Mortimer | Earl of Warwick | Thomas Wentworth, 1st Earl of Strafford | Edward Smith-Stanley, 14th Earl of Derby | Earl of Shrewsbury | William Pitt, 1st Earl of Chatham | Simon de Montfort, 6th Earl of Leicester | Richard Neville, 16th Earl of Warwick | Earl of Leicester | John Scott, 1st Earl of Eldon | Robert Devereux, 2nd Earl of Essex | Robert, 1st Earl of Gloucester | Edward Harley, 2nd Earl of Oxford and Earl Mortimer | Earl of Devon | Douglas Haig, 1st Earl Haig | My Name Is Earl | Edward Hyde, 1st Earl of Clarendon | Earl Scruggs | Earl of March | Richard Howe, 1st Earl Howe | John Russell, 1st Earl Russell |
During this time, Hopper also recorded and toured with a number of artists including Phyllis Hyman, Gato Barbieri, Roberta Flack, Gil Evans, Diana Ross, Earl Klugh, Jonathan Butler, Stephanie Mills, Johnny Gill, Gloria Lynne, Luther Vandross and Bryan Ferry.
He has performed internationally with jazz artists Nnenna Freelon (his mother), Herbie Hancock, Bob James, Earl Klugh, Patti Austin, Robert Glasper, Chris Dave and Derrick Hodge.
Other great musicians have collaborated throughout the years with the Urban Knights such as Maurice White (Earth, Wind & Fire), saxophonists Gerald Albright, Najee, Kenny Garrett and Dave Koz, guitarists Jonathan Butler, Norman Brown, Earl Klugh, Bobby Broom and Fareed Haque.