Tupper Saussy was a polymath and a fiercely intelligent libertarian. At his own online museum you could buy his music, books, films and paintings — the latter frequently featured brown-paper bags “because they contain, conceal, they transport and they are free”. When he dabbled in pop music at the end of the Sixties with his psychedelic group, the Neon Philharmonic, he was nominated for two Grammy awards.

Frederick Tupper Saussy III was born in 1936. He graduated from the University of the South in Sewanee, a liberal Tennessee college, in 1958.

A renowned charmer, he married a beautiful, wealthy young woman, Lola Haun. Saussy had been raised on Bach and Mozart but fell heavily into jazz at college — the couple even had a pet monkey called Thelonious Monk.

Saussy progressed from cartoonist for the college paper to the world of advertising. For fun, he would play in lounge bars. Seeing him play in 1960, Dave Brubeck came away telling people about a fine pianist called “cup and saucer”.

For a living, Saussy co-founded a Nashville advertising agency in the early 1960s to which he contributed jingles and slogans. The McDonald Saussy Advertising Agency made a name for itself with a campaign for Purity Dairies featuring a cow, a kangaroo and the slogan “Don’t pay no ’tention to kangaroos”.

Around the same time Saussy signed a deal with Monument Records, the Tennessee label that was also home to Roy Orbison. With the label he recorded such albums of other people’s work as The Swinger’s Guide to Mary Poppins.

His only significant composition from this period was The Beast with Five Heads in 1966, commissioned to provide Nashville public schools with an introduction to the orchestra — a latterday Peter and the Wolf.

By 1968 he had grown tired of advertising and, inspired by the Beatles’ Sergeant Pepper, teamed up with the singer Don Gant to form the Neon Philharmonic. By 1968 the barriers between serious pop, or rock, and every other colour on the musical spectrum had begun to blur. For an original such as Saussy, who loved writing for an orchestra, the new climate was encouraging, and his work fitted neatly alongside contemporary hits such as Mason Williams’s Classical Gas and Jimmy Webb’s MacArthur Park.

Warner Brothers signed the Neon Philharmonic and was soon rewarded with a US Top 20 single, Morning Girl, that picked up two Grammy nominations. The sweetness of the tune masked the fact that the lyric was less than romantic — it was about an older man deflowering a girl, and trying not to smirk about it in front of her over breakfast the morning after.

An album entitled The Moth Confesses followed and sold well, though this brand of soft rock was soon to become passé, vanquished by hard rock: as the Beatles abandoned lavish orchestration, Led Zeppelin signalled the future. After a second album flopped, the Neon Philharmonic was swiftly forgotten.

A clue to Saussy’s future lay in one of his songs, Are You Old Enough to Remember Dresden?. He explained that it was about “the way court historians warp truth to fit policy. I didn’t like the way Americans were oblivious of what US Armed Forces did to Dresden. Maybe the song is about the way our landscapes are spoilt by political systems. It’s probably outrageous that I failed to include a verse about what Washington DC did to the original Americans”.

The group’s eventual demise in 1972 coincided with the end of Saussy’s first marriage, and he abandoned music, taking solace in watercolour paintings — some of which can be found in the permanent collection of the Tennessee State Museum — and illustrating educational children’s books. He began to believe that the Internal Revenue Service was bullying him and studied tax and monetary law at the library of the University of the South in the late 1970s. The result was a book, The Miracle on Main Street. Its premise was that income tax was unconstitutional.

Saussy stuck to his word, defied the authorities, and in 1985 was convicted on three counts of wilful failure to file tax returns. The US District Judge, Thomas Hull, told Saussy: “You’re so intelligent it hurts you.”

To evade imprisonment, Saussy went on the run and lived as a fugitive, with supporters and friends all over the country hiding him from the police. He would occasionally frequent the Rainier Mall in Seattle, and play the Goldberg Variations on its 9ft Steinway. Finally, in 1997, a fellow fugitive gave him away and he was arrested.

During his 20 months in prison he wrote Rulers of Evil about “the influence of religious systems over secular governments”. It was published in 2001. Last April he returned to music, playing a well-received set of new songs under the conceptual name of The Chocolate Orchid Piano Bar in Nashville.

“It’s the ideal piano bar,” Saussy explained, “where only standards are played, standards nobody has ever heard before. One where the pianist sings his own songs that already seem familiar to you.” An album of the same name — his first in 37 years — was released this month, and he was lined up to promote it at the South Bank Centre, in London, in the autumn. At the time of his death Saussy was revelling in the good reviews he had also received for the digital repackaging of the Neon Philharmonic’s records.

He is survived by three sons and a daughter.

Tupper Saussy, musician, painter and writer, was born on July 3, 1936. He died of a heart attack on March 16, 2007, aged 70