The artistic director of the Mendelssohn on Mull festival, Levon Chilingirian, whose seventh year in charge begins on Sunday, confesses that he was told off by the event's trustees a couple of years ago. You can see their point. Although the chamber music concerts, in village halls, churches and castles, were still, indisputably on Mull, the repertoire being played by the specially-assembled groups lacked anything written by Felix Mendelssohn. A performance of the perennially popular Octet that the composer wrote as a precocious teenager was swiftly added to the programme.

If Mendelssohn on Mull strayed away from the composer whose visit to the island inspired it in recent years (and last year that included Apparitions, a new music site-specific theatre piece by Stephen Montague and some matching Shostakovich and Bartok), old Felix is back in the top spot for 2009, the 200th anniversary of his birth. The A major and B flat major string quintets will be played, alongside two of the string quartets. With Mozart and Dvorak represented by a single work, the bicentenary of the death of Joseph Haydn is also marked, with the younger players in each of the three groups taking responsibility for one of the Opus 74 quartets.

That is the sort of detail in the structure of the Mendelssohn on Mull programme that might easily be missed. The format of the event, which teams young professional musicians and music students about to take their first steps on the career ladder with seasoned mentors, was established by its creator Leonard Friedman. This year is its 21st birthday and Chilingirian, who played with Friedman as a youngster himself, has honed that structure so that it achieves particular educational aims as well as providing high quality free concerts for the island and its visitors, all without any public money.

"The most important thing Leonard did was get young players out of the city to a stunning island, away from the pressures of college life," says Chilingirian, a professor at the Royal College of Music in London. "There's too much sight reading and speed learning of orchestral works at music colleges. Going into music in depth is what we are not very strong at."

The young musicians who come to Mull will include a new intake of players from the Royal Scottish Academy of Music and Drama, recommended by the conservatoire. Others, like viola player Emma Stevenson, a former Douglas Academy pupil from Glasgow's east end who has just completed her post-graduate studies at the RCM, are Mull veterans.

"I've met some amazing people, and it has really opened my eyes to the possibilities for me as a musician," she says. Although there are no rules, she feels she should be thinking about freeing up a place so the Mull mentoring system moves on.

Chilingirian makes sure young musicians are given the scores they will be expected to know in plenty of time and factors in as much rehearsal time as possible. Crucially, as the three groups tour the island as well as Iona, they have the opportunity to perform all of their pieces at least three times.

Extra ingredients for Mendelssohn's birthday year include an arrangement of Fingal's Cave for string octet by Jonathan Cohen, which had its public premiere on the paddle steamer Waverley for the launch of the festival this month. Also onboard was Rick Jones, who cast himself as Mendelssohn.

Jones is a writer who has previously recreated journeys by Bach and Handel, costumed as the composers. He is on the road between Edinburgh and Tobermory, by way of Blair Atholl, Aberfeldy and Fort William, following the route Mendelssohn took in 1829, on the trail of locations made famous by Sir Walter Scott.

When he catches the ferry to Mull, it will be 180 years since one of the first scheduled steamer services left Fort William for the island, with the composer onboard.