Rob Horsting is a teacher and freelance pianist/arranger. Until 2000, he played with The Dual City Concert Band and the Millennium Jazz Orchestra (formerly Big Barchem Band). With the latter orchestra he recorded three CDs: Some Frames Of Mind (1992), Magnifying Glass (1997) and Triangular (2000). 

Rob Horsting played as an accompanist in various orchestras with Ferdinand Povel, Ack van Rooyen, Bart van Lier, Silvia Droste, Benny Bailey, Ruud Breuls, Jiggs Wigham, Jan Wessels, Lew Tabacking, Bobby Shew, Peter Tiehuis, Lee Konitz, Peter Weniger, Philip Catherine, Ernie Watts, Bob Malach, Ruud Ouwehand, Shebob, among others. He also played with the Big Barchem Band led by guest conductors Bill Holman, John Clayton and Jerry van Rooyen. 

Since 2000 he has worked intensively as an arranger with Henk Meutgeert. This resulted in numerous arranging commissions for The Jazz Orchestra of the Concertgebouw, but also for orchestras such as the Orchestra of the East, Ifiamminghi, the NNO, the Rotterdam Philharmonic, the Marine Band, the Air Force Band, various wind and brass bands, The Johan Plomp Orchestra and the Escher Ensemble. 

Soloists for whom he has written include Mike Mainieri, Astrid Seriese, Benjamin Herman, Dado Moroni, Roberta Gambarini, Ronald Snijders, Mike del Ferro, Carlo de Wijs, Matilde Santing, Toots Thielemans, Michel Portal, Richard Galliano, Cristina Branco, Alessi Bros, Deborah Brown, Roy Hargrove, Trijntje Oosterhuis, Ellen ten Damme, Jamesz, Izaline Calister, Stian Carstensen, Jimmy Heath, Johnny Griffin, Fay Claassen, Francien van Tuinen, George Coleman, Hugh Masekela, Pete Christlieb, Oene van Geel, Philip Catherine, Pat Martino, Opgezwolle, Jasperina de Jong, Chick Corea, and the World Tour Deep Purple 2000.