Paul Sexton's profile of one of the greatest pop vocal groups in chart history picks up at the end of 1967, as dusk was falling on the Four Seasons' incredible run of American hits.

The previous five years had brought four Number Ones among a total of 13 top ten classics, not to mention countless other widely-loved songs, some of which would become hits for others.

Paul Sexton explores the pressures that continued to pull the group apart, leading to the departure of another original member, Tommy DeVito, in 1971 (after Nick Massi left in 1965). DeVito had run up gambling debts that were bought out by the group in difficult circumstances. And, as both he and Frankie Valli confide, they did not talk again for many years.

But this episode also demonstrates that creative forces in the Four Seasons were still at work. In 1969, the group made the experimental album The Genuine Imitation Life Gazette, which unsettled those who wanted to keep them in their familiar pop vocal pigeonhole, but which has come to be regarded as an important transitional work.

Co-writer and producer Bob Gaudio also branched out by creating perhaps the greatest hidden gem in the entire catalogue of Frank Sinatra, 1970's Watertown album. He tells the story of that atmospheric record, and the time he invited Sinatra to his house for a swim - before remembering that he didn't have a pool.

Also featured are the songs that became belated UK hits via their club popularity and the Northern Soul circuit, Valli's You're Ready Now and the The Night, from their short stay at Motown. Valli discusses his massive solo success of the mid-1970s with My Eyes Adored You and Swearin' To God, which broke big even as he remained true to the re-emerging Four Seasons.

Arranger Charlie Calello, writer Denny Randell and 1970s Season Lee Shapiro all contribute to the programme, which culminates with the group riding the top ten once again with Who Loves You and December 1963 (Oh What A Night). Show less