Not many British guitar players took lessons from the Rev Blind Gary Davis, the legendary “Harlem street singer” whose style influenced the Grateful Dead, Bob Dylan and Wizz Jones.

Fewer still were young Scottish aristocrats. But in 1956 two brothers from the Scottish Borders went on a tour of the United States, taking their guitars with them. In the course of it Rory and Alex McEwen picked up an eclectic mix of jazz, folk and blues, which they combined with their own knowledge of Scottish folk music. By the time they returned, having learnt from Davis and many others, they were in the vanguard of the folk song revival.

For years afterwards the McEwen brothers were familiar to British audiences, through their regular slot on the Tonight programme on BBC, their appearance at London clubs, the Edinburgh Festival, and a celebrated night at the Royal Festival Hall with the Clancy Brothers and Tommy Makem.

Among those who watched them on television was the Belfast-born musician Van Morrison, who told guests at a party at Jools Holland’s house recently that the McEwen brothers had been one of his early inspirations.

Alexander Dundas McEwen, known universally as Eck, was born at Marchmont, an Adam house in Berwickshire, the son of Sir John and Lady Bridget McEwen of Marchmont and Bardrochat, whose mother had been a Lovat Fraser. Sir John, Tory MP for Berwickshire and chairman of the backbench 1922 Committee, was later made a baronet. In the 19th century the McEwens had married into the Finnie family whose principal claim to fame — and fortune — was that they had built the harbour at Rio de Janeiro; it was the 19th-century Robert Finnie McEwen who acquired Marchmont in the Borders and the Ayrshire house of Bardrochat. A glittering family, blessed with good looks and celebrated charm, the McEwens were, however, touched by tragedy. All the brothers, bar Alexander and his brother John, died young. Indeed, Alexander outlived his elder brother Rory by 26 years.

A strain of undoubted eccentricity ran through the family. Sir John thought it quite normal, indeed practical, to save money on a new car by buying an old chassis and commissioning the local carpenter to build the body, which he did in yellowed pine, with plate glass windows — the machine was known thereafter as the Flying Banana. He encouraged his children to shrink away, when their mother attempted to introduce them to strangers, but at the same time he taught them all good manners. A convert to Catholicism, Sir John and his wife brought up all their children in the Catholic faith.

Alexander was educated at Eton and did military service in the Cameron Highlanders. During his service he had to be relieved of duties defusing unexploded bombs owing to what was described as too cavalier an approach to danger.

He had acquired his enthusiasm for music from his brother Jamie, an artist, and, after leaving the Army, he and Rory planned a three-week road trip across the US, plotting their route on a world map spread out on the billiard table at Marchmont. Their musical pilgrimage took them from New York, through the Blue Ridge Mountains to Louisiana and on to New Orleans where the music of Leadbelly and Blind Boy Fuller provided much inspiration, before finally ending up in Hollywood, where they were invited on to The Ed Sullivan Show on two consecutive nights.

On their return to New York they appeared on The Arthur Godfrey Show, and were asked to come back on two more shows, The New York Times remarking in its review, “their impact was entirely out of proportion to their talent” — “a veiled compliment, I suppose”, Alexander remarked later.

After a year Rory came home and Alexander stayed for another year, playing in the Village, where he was once backed by Dylan. On his return to Britain in 1958 he found himself the earliest proponent of true delta blues this side of the Atlantic. His sessions on the Tonight programme with Rory included a nightly topical calypso, with lyrics by Bernard Levin. This was followed by his own programme, Alex Awhile on Scottish Television, playing a mixture of blues, American and British folk, Scottish ballads, calypso — almost anything, in fact, that involved a guitar and a memorable voice.

In late 1958 he met Cecilia Weikersheim, the only child of Prince and Princess Weikersheim, who had escaped Hitler and come to Britain from Austria before the war.

On the birth of their third child in 1965 he gave up performing and recording as a professional musician and opted for a career in commerce. He joined John Menzies, the Scottish newspaper distributers and retailers, at the lowest level, and eventually reached the board as personnel director, a position for which he was eminently qualified — an aptitude test in New York had suggested a career as an aptitude tester.

He worked for John Menzies for 20 years, commuting to Edinburgh from his farmhouse in the Borders, and latterly from Bardrochat, the large, rambling Lorimer house in Ayrshire built by his grandfather and previously inhabited in his generation by two of his elder brothers. In 1985, aged 50, he took early retirement from John Menzies, more or less as his youngest child stepped out of university.

He settled on the West Coast of Scotland, there to spend the following 22 years running what he described as the worst pheasant shoot in Europe, fishing on the Stinchar in South Ayrshire and trying to support a large house with little land in rural Scotland. To this end he had a successful art dealing business, selling Scottish Colourists long before the market peaked, and renting Bardrochat out as a location for photographic shoots.

In 2005, as the money ran short, he sold Bardrochat and moved to Dalreoch House a couple of miles away, and to a house in a medieval Venetian village in Croatia that he and Cecilia rebuilt from the cellar up.

A wise and knowledgeable countryman, who took both rural affairs and his religion with great seriousness, McEwen was a man of enormous charm, impeccable manners, and possessed of a boundless, if occasionally lateral, sense of humour.

He leaves a wife, daughter, and two sons.

Alex McEwen, musician and businessman, was born on May 16, 1935. He died of a heart attack on December 6, 2008, aged 73