The Castalian Quartet is rapidly emerging as an exciting voice on the international chamber music scene

Named 2019 Royal Philharmonic Society Young Artist of the Year, their recent and forthcoming highlights include debut invitations to Carnegie Hall, Vienna Konzerthaus, Paris Philharmonie, Auditorium du Louvre, Amsterdam Concertgebouw, Lucerne Chamber Music Society, Brussels Flagey, Tel Aviv Museum of Art, Saffron Hall, and the Aldeburgh, East Neuk, Spoleto, North Norfolk, Heidelberg Spring, Rheingau, Mosel, and Dresden festivals. The Quartet’s 2019-2020 Wigmore Hall cycle of Brahms and Schumann featured collaborations with Stephen Hough, Cédric Tiberghien, Michael Collins, Nils Mönkemeyer, Isabel Charisius, and Ursula Smith. In 2018, they recorded the complete Haydn Opus 76 quartets for the Wigmore Live label.

Formed in 2011, the Castalian String Quartet studied with Oliver Wille of the Kuss Quartet at the Hannover Hochschule für Musik, soon winning 1st Prize at the 2015 Lyon Chamber Music Competition and 3rd Prize at the 2016 Banff International String Quartet Competition. Their influential teachers to date include Simon-Rowland-Jones, David Waterman, and Isabel Charisius. In 2016, the Quartet were selected by the Young Classical Artists Trust, and more recently were named recipients of the inaugural Merito String Quartet Award/Valentin Erben Prize and a 2018 Borletti-Buitoni Trust Fellowship.

In only a few seasons, the Quartet have made critically-acclaimed debuts at New York’s Lincoln Center, Banff International String Quartet Festival, the Vancouver Recital Series, Montreal’s Salle Bourgie, and The Philips Collection in Washington D.C. Other highlights include performances at the Hamburg Chamber Music Series, International Musikfest Goslar, Sommerliche Musiktage Hitzacker, and the Bath, Cheltenham, North Norfolk, Peasmarsh, and Winchester festivals. They were also the resident ensemble at the Esbjerg International Chamber Music Festival in Denmark. Their many notable collaborators have included Aleksander Madzar, Alasdair Beatson, Simon Rowland-Jones, Daniel Lebhardt and Olivier Stankiewicz.


Our Story

Who we are and how we met

Let’s begin with the final piece of the puzzle. Our first violinist, Sini, is a nomadic, polyglottic Finn, often sighted with a tennis racquet slung over her shoulder as well as a violin case. We found her in Hannover, Germany, where she was completing her solo degree as we were studying for a Masters in Chamber Music. One day she flung a hopeful message into cyberspace stating her desire to play string quartets. Fortuitously, it landed in our email account and the rest, as they say…

Charlotte and Daniel form our inner parts. She is a vegan violist who can tie herself into baffling yogic knots. He is a steak-loving second violinist with dodgy knees. She’s French, brought up high in the Alps. He’s Welsh, brought up at the foot of Ben Nevis. Charlotte’s first love is her Siberian cat Lancelot. Daniel’s is Liverpool Football Club. She went to the Royal Academy of Music. He went to the Royal College of Music. She’s petite. He isn’t. Otherwise, they’re inseparable, our Chaz and Daz, and have been ever since the Castalians’ first bow-strokes back in 2011.
Two years earlier, Daniel arrived in London to commence his studies at the College. A local cellist with a plummy accent took pity on this wide-eyed chap from up North and befriended him over lunch in nearby Hyde Park. On his return from a postgraduate course in Lugano, Chris joined the quartet. Since then he’s been whetting our appetites with culinary wizardry and wetting watercolour blocks with landscapes of our travels.

Today, we all reside in London, rehearsing in South Kensington and giving concerts everywhere from the Wigmore Hall to Warren Hill prison, Carnegie Hall to the Colombian rainforest.

It’s some journey being in a string quartet, and one we feel immensely lucky to take together.

Our name is derived from the Castalian Spring in the ancient city of Delphi. According to Greek mythology, the nymph Castalia transformed herself into a fountain to evade Apollo’s pursuit, thus creating a source of poetic inspiration for all who drink from her waters. Herman Hesse chose Castalia as the name of his futuristic European utopia in The Glass Bead Game. The novel’s protagonist, a Castalian by the name of Knecht, is mentored in this land of intellectual thought and education by the venerable Music Master.

Sini Simonen - Violin

The Finnish violinist Sini Simonen enjoys an active international career as a chamber musician and soloist. She is the leader of Castalian String Quartet and the violinist of Calvino Piano Trio.

Simonen has won top prizes in several major international violin competitions including the Flesch, Lipizer and Cremona competitions. She has also won prizes in the Brahms, Lyon, ARD, Banff and Citta di Pinerolo chamber music competitions.

She studied in Sibelius Academy, Musikhochschule Hannover and Musik-Akademie Basel with Lara Lev and Rainer Schmidt among others. Masterclasses and collaborations with Ferenc Rados, Gerhard Schulz, Sir Andras Schiff, Miriam Fried, and Ursula Smith provided important influences.

From 2013 to 2017, Sini was a violinist of Esbjerg Ensemble, one of Denmark’s oldest chamber groups. The ensemble is comprised of a string quartet, wind quintet and percussion, and it is known for its innovative programmes combining contemporary and classical music.

She has appeared as a concerto soloist with orchestras including Stuttgart Chamber Orchestra, Cologne Chamber Orchestra, Göttingen Symphony Orchestra and Trondheim Symphony Orchestra. Her cd recordings as a soloist include Bach’s double violin concerto with Helsinki Strings (Warner) and Vivaldi’s concerto for 3 violins (tacet).

Her chamber music partners have included Ferenc Rados, Robert Levin, Midori and Steven Isserlis.


Daniel Roberts - Violin

Daniel Llewellyn Roberts (b.1987) studied with Nigel Murray and Jan Repko. He is a graduate of the Royal Northern College of Music, Manchester, holds Masters degrees from the Royal College of Music, London (as a Yehudi Menuhin Scholar), and the Hochschule für Musik, Theater und Medien, Hannover, and has twice been a Leverhulme Chamber Music Fellow at the Royal Academy of Music, London.

As a soloist, Daniel has appeared in Hong Kong City Hall, the Queen’s Hall, Edinburgh, the Hindemith Cabinet, Frankfurt, and the Sudler Recital Hall, Yale University. He was the recipient of the 2009 Musicians Benevolent Fund ‘Emily English’ Award for ‘most outstanding violinist’, and the 2010 Philharmonia Orchestra MMSF ‘John E. Mortimer’ prize.

Alongside his role as violinist with the Castalian String Quartet, he performs internationally as a chamber musician and has collaborated with musicians such as Simon Rowland-Jones, Tom Poster, Levon Chilingirian and the Primrose Piano Quartet.

Daniel is in demand as both a violin and chamber music teacher, previously holding positions at Birmingham Conservatoire and St. Paul’s Girls’ School, London, and giving masterclasses at St. Mary’s Music School, Edinburgh, and in various music schools and conservatoires in China. He teaches on the Xenia Chamber Music Course in Italy.

Daniel is a Yeoman of the Worshipful Company of Musicians and is extremely grateful to them for the loan of a fine violin by Joseph Guarneri filius Andrea of 1705.

Charlotte Bonneton - Viola

Having studied in her native France at the Grenoble Conservatoire and the Schola Cantorum, Paris, Charlotte was awarded a full scholarship to study violin with Professor György Pauk at the Royal Academy of Music, London, where she obtained a Bachelor of Music with First Class Honours and a Master of Arts with Distinction. Whilst at the Royal Academy, Charlotte also studied viola with Matthew Souter.

Aged 16, she won 2nd Prize at the Wieniawski International Violin Competition (Junior Category) and subsequently performed as a soloist in the Maison de Radio France, the Auditorium du Louvre (Paris), the Salle Cortot (Paris), the Théâtre des Bouffes du Nord (Paris) and the Festival Radio-France in Montpellier. In 2011 she made her recital debut at the Concertgebouw, Amsterdam, as part of the Holland Music Session’s ‘New Masters on Tour’ programme.

As a concerto soloist, she has appeared with Orchestre National de Lorraine, Jyväskylä Sinfonia, Kazakh State Philharmonic Orchestra, Wroclaw Chamber Orchestra Leopoldinum, Royal Academy String Orchestra and Royal Academy Concert Orchestra, performing works by Mozart, Mendelssohn, Saint-Saëns and Schnittke.

Charlotte is dedicated to introducing audiences to new music and regularly collaborates with the London Contemporary Orchestra.

Christopher Graves - Cello

Christopher Graves studied the cello with Melissa Phelps at the Royal College of Music and with Johannes Goritzki at the Conservatorio della Svizzera Italiana. He studied chamber music with Oliver Wille at the Hochschule für Musik, Theater und Medien, Hannover. His other teachers have included Bernard Greenhouse and Kate Beare. During his studies he was awarded scholarships by the Countess of Munster Musical Trust, the Musicians Benevolent Fund, and the Martin Musical Scholarship Fund.

Aside from his activities with the Castalian Quartet he has performed widely as a chamber musician in the UK and abroad, at venues such as the Wigmore Hall, Cadogan Hall and Kings Place, and played at festivals such as the Middelburg International Festival and Kings Place Festival. As a soloist he has been heard on BBC Radio 3 playing in the BBC Proms Plus festival with an RCM chamber orchestra, and has given recitals in the UK and Europe.

As a teacher he has coached chamber ensembles at the Royal College of Music, Birmingham Conservatoire and Chethams Music School. He has played principal cello with orchestras such as Scottish Opera and Sinfonia Cymru and worked with other orchestras including the Philharmonia.