Expect the unexpected at Cambridge Folk Festival. Top Celtic musicians, McGoldrick, McCusker and Doyle, on uillean pipes, guitar, whistles and fiddle, treated us to a tune called Nando's Jig. We were told: "John went into Nando's for dinner. A guy came in and went down on one knee to propose to his girlfriend - in Nando's! "She said: 'We have to talk'. So we wrote Nando's Jig. Another of their pieces was called Will You Please Stop Playing the Trumpet. Said McCusker: "We were playing and there was a squeaky noise at the back of the theatre. I thought I heard a trumpet at the back of the hall. I said can anyone hear a trumpet? And there was a guy playing the trumpet to music he had never heard before. "I don't know about you but I don't think you should bring your trumpet to a gig." Joyous reels and jigs were interspersed for the main tent's Sunday afternoon audience with songs to break your heart. One was Memorial Song for people who tried to escape the Irish famine by going to Canada by ship, some 30,000 who never made it, they died of typhus or ship fever. Played on flute, guitar and fiddle, the gentle movement of sea is in the melody. The chorus was Sailing to Liberty's Sweet Shore. "The clothes on our backs are all we own. We've left all we've known. For this new life, we're going." There were several references to the plight of refugees during the festival. The Cambridge audience does not leave its conscience at the gate, it is more likely to wear it on a t-shirt. And if they do forget, they will be reminded from the stage. There was a lively song about the grave robbers Burke and Hare, two Irishmen who went to Edinburgh and began supplying medical students with bodies. They decided it was easier to kill people than to dig the graves up. They were informed on by one of their wives who thought she might be next. They had turned their attentions to friends and family. But the most beautiful tune was a waltz written by one of the three when he was aged 18, a wistful melody about the sadness of leaving a harbour. Next up on Stage One was something completely different. Imarhan are supreme rock guitarists from Southern Algeria. This is sheer rock guitar with African-style drumming - and stupendous. Long sequences of guitar, building and building. Magnificent. They sing in the Tamashek language, which is disappearing. Then another complete change of style with The Unthanks. Rachel and Becky, the two singing sisters from Gateshead, are now big favourites at the festival. On Saturday night in the smaller, Club Tent, they sang a cappella. On the main stage on Sunday, they were with a 10-piece band, including Rachel's husband, pianist Adrian McNally, trumpeter Liz Jones, plus drums, guitars, violins and cello. It is a wonderful sound. Their stories and songs make people laugh and cry. Adrian had been asked by the Bronte Society in Haworth to put music to one of Emily Bronte's poems. "The night is darkening around me. The loud winds coldy blow. But a tyrant's spell has bound me. And I cannot, cannot go." The sisters' clear voices paused for some beautiful, unforgettable trumpet solos from Liz Jones which had the audience holding its breath. The moving finale was their lifting song about Charlie's pidgeons: "In the West End of Derby, there's a man. Who says, I can't fly but my pigeons can." Other Sunday highlights were The Blind Boys of Alabama. These now veteran singers, winners of five Grammys, were only on for a couple of numbers, but one of them was Spirit in the Sky. They still have voices to blast the roof off. With them were Amadou and Mariam getting the main tent dancing to the music of Mali with Afro-pop. Meanwhile, over on stage two, the tent was overflowing for an evening session by The Fishermen's Friends. The-one-who-did-the-talking said five of them were called John. He spoke about the film that has made them even more famous: "Yet another television crew arrived in Port Isaac for a documentary on inbreeding. Father's day is the most confusing day of the year." The powerfully sung sea shanties delighted the audience with none of this old politically correct nonsense. If you want to haul up ropes, you need to get your spirits up with notions of friggin in the riggin. The grand finale, closing the festival on the main stage, was Daoiri Farrell's All-Star Celtic Session: Farrell was with Michael McGoldrick, Donal Lunny, Niamh Dunne, Sean Og Graham, Donald Shaw and Robbie Walsh, so bodran, uillean pipes, accordion, fiddle, violin and guitar. Donal Lunny from Planxty sang The Galway Girl, Niahm Dunne on the fiddle also sang - wonderfully, a beautiful voice to stop you in your tracks. But the rest was dancing and dancing to joyous playing, played with delight and heard with rapture, until we wandered out into the night and were wished a safe journey home. The day had been full of music that was a privilege to hear.