Active as a soloist and chamber musician Ashley is the director of Florilegium, and much of his time is spent working and performing with this ensemble that he founded in 1991.

As a soloist, he has performed worldwide, including concertos in the Sydney Opera House, Esplanade (Singapore), Teatro Colon (Buenos Aires), Concertgebouw (Amsterdam), Konzerthaus (Vienna), Beethoven-Haus (Bonn) and Frick Collection (New York). He also records as a solo artist with Channel Classics and his recording of the complete Bach’s Flute Sonatas was voted the best overall version of these works on either modern or period flute by Gramophone Magazine (February 2017):

'Solomon’s luminous tone and unfussy command of the complicated melodies conflate into something utterly beautiful. Slow movements are soulful in their infinite variety, fast ones are clever and with a wealth of invention behind them.'

Since 2019 Ashley has been involved in a unique recording project using a collection of 17th and 18th century flutes from a private collection in Frankfurt. To date he has released 3 volumes in the Spohr Collection series involving 25 rare and original 1-keyed baroque flutes made of ivory, boxwood, ebony and porcelain. This project has given new insight into the sound world of European flute makers in the baroque period and contextualises each flute both historically and geographically.

Since 2003 he has been training vocalists and instrumentalists in Bolivia, working in collaboration with Dr Piotr Nawrot on the remarkable collection of music held in archives of the Moxos and Chiquitos Indigenous peoples. He formed Arakaendar Bolivia Choir in 2005 and Arakaendar Baroque Orchestra in 2007 with APAC and has directed them in concerts throughout North and South America, Europe and in the Far East and on their 3 cd recordings. In 2008 Ashley received the prestigious Bolivian Hans Roth Prize, given in recognition of the enormous assistance he has given to the Bolivian musicians, their presence on the international stage and the promotion and preservation of this music.

Combining a successful career across both theory and practice, Ashley is Head of Historical Performance at the Royal College of Music, having been appointed a professor in 1994. In 2014 he was awarded a Personal Chair and in July 2017 he was elected a Fellow of the Royal Academy of Music (FRAM) which was conferred on him by HRH Duchess of Gloucester. In 2019 he was also elected a Fellow of the Royal College of Music (FRCM) which was conferred on him by HRH Prince of Wales. Both Fellowships are in recognition of outstanding services to music.