She is a regular guest at international festivals such as the Delft Chamber Music Festival (Netherlands), the Lofoten Festival (Norway), the International Schubert Festival in Steyr (Austria), the International Musician's Seminar in Prussia Cove and Spannungen in Heimbach (Germany), where she recently performed as soloist alongside Antoine Tamestit in Bach's Brandenburg Concerto No. 6 for two solo violas. All concerts from that festival were broadcast live on National German Radio and have now partially been released as CDs on the CAVI label. In 2007 she participated in a chamber music Gala Concert at the Alte Oper in Frankfurt alongside Gustav Rivinius and Lars Vogt, and more recently in 2008 she performed chamber music with Renaud and Gautier Capuçon at the Wiener Festwochen in the Grosser Saal of the Musikverein in Vienna. In October 2008 she performed as soloist alongside violinist Benjamin Schmid with Christoph von Dohnányi conducting the Philharmonia Orchestra in a performance of Mozart's Sinfonia Concertante at the Royal Festival Hall. In 2009 she will be playing chamber music in Hamburg at Festival Ostertoene playing with Antje Weeithaas, Christian Poltera and Lars Vogt. Other chamber music highlights in 2009 include Heimbach Spannungen Music Festival in Germany in June, in July the chamber music festival Hindsgavl in Denmark, in August appearing with the Nash ensemble at Windsor festival, and also recitals in Germany at Schloss Elmau in August and Aachen in October. In 2010 she will be recording the Brahms sonatas for viola and piano with pianist Lars Vogt, also on the CAVI label.

Rachel Roberts has held the post of Joint Principal Viola with the Philharmonia Orchestra since 2000. She has appeared as soloist with them at the Royal Festival Hall, St. John's Smith Square, London, Leicester's De Montfort Hall and St George's Chapel in Windsor Castle. As part of their contemporary music series, Music Of Today, she has appeared as soloist at the Queen Elizabeth Hall and the Royal Festival Hall performing world premières by Tristan Murail and Derek Bermel. With the Orchestra she has made numerous CD recordings and has toured America and Europe working with conductors such as Riccardo Muti, Kurt Sanderling, Lorin Maazel, Evgeny Svetlanov, Charles Dutoit, Christoph von Dohnányi and Vladimir Ashkenazy playing at venues including Carnegie Hall and the Lincoln Center- New York, Musikverein - Vienna, Tonhalle (Zurich), Theatre du Chatelet (Paris), Philharmonie Hall (Berlin), Concertgebouw (Amsterdam), the National Concert Hall in Madrid, and La Scala, Milan. She has guest led the viola sections of the London Philharmonic Orchestra, the Covent Garden Opera House and London Sinfonietta.

From September 2009 Rachel Roberts will hold a teaching position at the Guildhall School of Music and Drama in London.

Rachel Roberts plays a viola by Gaspare Lorenzini dating 1786, and would like to thank the Tertis Foundation and the kind individuals that generously assisted in its purchase.

The Philharmonia's Principal Viola's Chair is endowed in perpetuity by The Tertis Foundation.