His debut album (Ring, Ring, I've Got To Sing) is a mixture of skiffle, folk and improvised blues music. After that album and the unexpected international success that followed, things started to go wrong. One example is Johnny Hallyday who had a hit with "Cheveux longs, idées courtes" which was a copy of one of Grignard's arrangements, but Hallyday didn't pay royalties for it.
Grignard changed record-companies from Philips to Barclay, but the first Barclay-album "Captain Disaster" didn't do as well as expected. Two come backs (early and late seventies) failed as well.
He died in Antwerp of throat cancer in 1982, at that time he was living on an attic without heating, surrounded with empty bottles.
His music and legacy has inspired many other groups like dEUS, Zita Swoon and Roland Van Campenhout for instance.