Violinist, instrument collector, bow maker, restorer and jeweller – these are the many lives of Henryk Kaston, one of the most venerable figures on the New York music scene. An extremely fit 95-year-old, he happily reveals the secret of his longevity and youthful vigour by demonstrating his morning exercise routine, which includes 60 press-ups and sets of violent kicking and shoulder-shrugging moves.

Kaston was born in Piotrków Trybunalski, Poland, in 1910 and began studying the violin with his father and grandfather at the age of eight. When he was 15 he spent a year as a member of a local ensemble that provided musical accompaniment for silent films, though within two years he had abandoned music – temporarily, it transpired – and joined a circus as an acrobat, one of many colourful occupations he pursued in his youth.

In 1937 Kaston resumed his musical studies and, with the encouragement of his family, travelled to Paris to have lessons with Enescu. He arrived with his wife, Maryna, on the day of Ravel's funeral, which they attended. While studying in Paris, Kaston became close to many musicians, among them the famous Polish harpsichordist Wanda Landowska, whose harpsichord he tuned, and the pianist, composer and future prime minister of Poland Ignacy Paderewski. He also befriended Chagall, Picasso and Maillol, and has ended up a lifelong friend of Maillol's curvaceous muse Dina Vierny.

When the Second World War broke out, Kaston volunteered for a special Polish cavalry regiment of the French army and, true to form, took his violin with him to the front. He was wounded and captured by the Germans, but he disguised himself and escaped from the little French farmhouse where he was being held by dressing in the farmer's work clothes.

He was officially demobilised in 1941 and, along with his wife, was taken under the wing of the Emergency Rescue Committee. This was headed by the American humanitarian Varian Fry, whose personal mission was to relocate artists, writers, intellectuals and musicians who were threatened by the Nazis. They set sail for New York from Marseille, but the journey was not without event, and their son Joseph was born during the dangerous transatlantic passage.

Kaston soon secured a violin position in the Cleveland Orchestra, playing under Artur Rodzinski and Erich Leinsdorf. Rodzinski would carry a pistol to rehearsals. 'Not to intimidate the orchestra,' Kaston points out. 'Quite the contrary – he was not on good terms with the players and was deathly afraid of them.'

As a chamber musician, Kaston has performed with many distinguished artists, but none more eminent than when, one day in 1947, he was asked to make up an informal foursome at a friend's Manhattan apartment and found himself playing quartets with Isaac Stern, Alexander Schneider and Albert Einstein – the towering pillar of 20th-century science and an enthusiastic, if not superbly talented, amateur violinist. 'Einstein would take the train from Princeton to join in on these sessions,' remembers Kaston. 'He had a special love of Mozart but unfortunately he was not a very good player – he was always lagging behind the other musicians. Finally one day the violist lost his temper and roared: 'The trouble with you, Mr Einstein, is that you can't count! It's one, two, three, four!''

Kaston had joined the orchestra of New York's Metropolitan Opera in 1943 and played in the violin section for more than 35 years, living in a studio apartment above the opera house until the company moved to the Lincoln Center in 1966. He recalls how the tempestuous Italian conductor Arturo Toscanini, if he was not happy with the orchestra's playing during rehearsal, would pull out his pocket watch and hurl it to the floor, sending pieces flying everywhere. Kaston witnessed this drama many times and was amazed by the spectacle – until he discovered that Toscanini bought the watches in bulk at a five-and-dime store.

The most memorable evening Kaston ever spent in the opera pit of the Metropolitan Opera was probably 4 March 1960, when Leonard Warren was singing the role of Don Carlo in Verdi's La forza del destino. 'He was a good friend and a fine baritone,' Kaston recalls. 'While singing the title aria, 'It is my destiny to die,' he suddenly clutched his chest and dropped dead on the stage from a heart attack. It was the only time I can remember that the show did not go on. It was the one night they closed the opera.'

While living in New York, Kaston developed his interest in violin bows and became a highly respected maker and restorer. He worked part-time at the Wurlitzer shop during the 1960s, rehairing bows, making skilful repairs and serving as the firm's resident bow expert. Many of the replacement fittings that he made at Wurlitzer's were so well crafted that they later passed, or were passed off, as original. His reputation has suffered somewhat as a result, although he insists it was never his intention to deceive, but rather to provide convincing replicas of fittings when the originals were missing or beyond repair. Where possible, as when making a new frog for an old bow, he has always engraved his initials in some discreet recess to aid future identification. This is not failsafe, however, and Kaston recalls that he was once asked to authenticate a Tourte bow which he certified as original in all its parts. After purchasing it, the new owner brought it back to Kaston for rehairing, who was shocked to discover his own initials in it when he removed the frog – he had misidentified his own work as Tourte! An unfortunate consequence of Kaston’s remarkable skill has been the downgrading of some authentic Tourte bows as Kaston copies.

As his restoration work went on, Kaston developed a special interest in Tourte. Surprisingly little was then known about this important figure, credited with the design of the modern violin bow, and Kaston and his wife began an exhaustive search in the French archives for biographical information on the Tourte family. They discovered over 30 unpublished documents, which became the basis of a magazine article (The Strad, April 1999) and a scholarly book – Francois-Xavier Tourte: Bow Maker – which I co-authored with Mary Laing (published in 2001 by Machold Rare Violins).

Kaston has made bows for some of the great violin virtuosos, including Heifetz, Kreisler, Stern and Shlomo Mintz, and a quartet of his presentation bows is in
the permanent collection of the Smithsonian Institution. In 2003 one of Isaac Stern's Tourte bows with a replacement tortoiseshell and gold-mounted frog made by Kaston was sold at Tarisio Auctions. It had been estimated to go under the hammer at $40,000–50,000, but fetched $102,500, an auction record for a Tourte bow – and a composite one at that.

The bow maker has vivid memories of Heifetz, a notoriously difficult peron. 'He was very secretive and did not want anyone to know his business,' says Kaston. 'He was estranged from his children and other members of his family, and he had few close friends. Herbie Katzman once asked me to secure Heifetz's help in advancing the career of the young Isaac Stern, but he flatly refused.' Heifetz was fond of Kaston, however. 'Why he liked me, I do not know. He would sometimes let me carry his violin case for him; no one else was ever allowed to do that. I invented a little rubber mute which we patented together and marketed as the Heifetz mute. It's a very successful design that is still widely used. He bequeathed his Guarneri violin to the San Francisco Museum of Fine Arts along with a special presentation bow I made for him. I am very proud of that.'

Kaston's knowledge of bows is prodigious and many dealers and violinists have relied upon his expertise. The late Jacques Francais frequently called upon him to help identify or authenticate a bow and Stern would never have considered purchasing a bow without first asking him to look at it.

As well as bows,