Madness frontman Graham “Suggs” McPherson has sung at a vigil attended by hundreds of people for a 21-year-old filmmaking student who was stabbed to death in a north London park . Suggs sang “It Must Be Love” as balloons were released in memory of Finbar Sullivan , who was stabbed during a fight in Primrose Hill in the early evening of April 7. Famous faces turned out along with friends and family at the viewing point on Primrose Hill on Sunday evening. They included musician Paul Weller, Dexys Midnight Runners frontman Kevin Rowland, Primal Scream frontman Bobby Gillespie and The Sex Pistols bassist Glen Matlock, organisers said. Finbar Sullivan's parents Leah Seresin (left) and Chris Sullivan (centre) join a vigil on Primrose Hill, north London, in memory of the 21-year-old filmmaking student (PA) Dozens of candles and bunches of flowers were placed at the gates to the park, along with pictures of Mr Sullivan. Some of his favourite songs were sung and a minute’s silence was held.…