After Marlborough he gained a place at Manchester University to read Politics, Philosophy and Economics, but he only lasted one term. During the summer before he started his degree he had been introduced to a young singer called Jay Kay by a mutual friend, Joe (the 10th Earl of) Hardwicke. He decided to jettison university and pursue a career in music.

Jamiroquai’s first gig was at The Fridge in Brixton, and not long afterward the band signed an eight-album deal with Sony. The ensuing 10 years saw prolific song writing, with hits such as Emergency on Planet Earth, Return of the Space Cowboy, Cosmic Girl, Virtual Insanity, Deeper Underground and Too Young to Die penned mainly by Grafftey-Smith and Jay Kay, with original band members including Stuart Zender, Nick Van Gelder and Wallis Buchanan.

As Grafftey-Smith once explained: “All the most successful tracks Jay and I wrote happened within a quarter of an hour, and were more-often-than-not a combination of a verse of mine plus a chorus of his, or vice versa. … Virtual Insanity was a verse I had written at home, with a chorus that Jay had written while on tour in Japan.”

Jamiroquai succeeded, in his view, “because we had a lucky combination of timing, skill and individuality in a time dominated by Beatles cover bands and dance music”.

Virtual Insanity won a Grammy in 1997 as well as four gongs at that year’s MTV Video Music Awards. Grafftey-Smith, with what his mother Lucy called a “total disregard for outward career plaudits”, lost one award in the back seat of a taxi.

Jamiroquai released their debut album Emergency On Planet Earth in 1993, after which the band notched up four UK No 1 albums, nine UK Top 10 singles and total record sales of 26 million.

Grafftey-Smith left Jamiroquai after a decade in the group, and a gruelling schedule of international touring, to devote more time to his family. At his home in the country he built Angelic Studios with the ambition to create “an atmosphere of creative and restrained calm”, where performers could make use of his unrivalled collection of keyboards.

There he hosted artists such as Mumford & Sons, Black Sabbath and Emeli Sandé, and produced and managed the English rock band The Hoosiers. He also co-wrote with One Direction, Olly Murs, Will Young and Ella Henderson and co-produced Matt Cardle’s third album Porcelain.

Meanwhile with two local friends, the food writer William Sitwell and the artist Jasper Galloway, he co-founded a cider brand, 3Cs. His unconventional approach was refreshing in the stodgy corporate world of drinks retailing.

Grafftey-Smith, who faced a diagnosis of cancer six years ago with defiant nonchalance, is survived by his wife, Gabriella, and their three children Anastasia, Dylan and Rose.

Toby Grafftey-Smith, born October 29 1970, died April 11 2017