Anyone who remembers the late Leo Maguire's gentle voice exhorting radio listeners "if you feel like singing, do sing an Irish song" will automatically think of Waltons - the family-owned music store which coined the memorable phrase.

Traditional Irish music is still an important part of business at the two Waltons shops on North Frederick Street and South Great George's Street. But so is Cuban guitar music, classical piano and violin, rock 'n' roll and percussion.

Both stores are a veritable wonderland of musical instruments, sheet music and hi-fi equipment. Guitars in every hue from baby pink to electric blue decorate the walls.

Further in, entire drum kits beg to be tested and the latest in classical instruments and hi-fi equipment are on display. At weekends, the shops are full of budding young musicians trying out the wide selection of instruments.

Upstairs in South Great George's Street, a school of music provides tuition in the instruments and recording technology sold in the shop. Niall Walton - the third generation to run the family empire - attributes the company's phenomenal success to its adaptability and a talent for enduring despite seemingly insurmountable odds.

"If you look at the perpetual struggle to survive, perseverance is the only thing when times are bad," he says.

Niall's grandfather Martin was interned at Ballykinlar camp during the War of Independence, and this was the unlikely inspiration for the first Waltons shop. Martin was asked to set up a prison orchestra; when instructed to sell the instruments after the war, people "queued up" to answer the newspaper advertisement.

The South Frederick Street shop opened in 1922 and traded through the War of Independence, the Civil War and the Wall Street Crash in 1929.

"Just when things were getting better, De Valera declared economic war on England in 1933," says Niall. "World War Two started in 1939 and you couldn't buy a musical instrument anywhere. My grandfather went into market gardening to survive and started manufacturing instruments in Ireland.

"If you took pictures of the shop back in the 1920s and 1930s, it was nearly all fiddles. Then the accordion took over and, when I was a child, it was wall-to-wall accordions."

"In the big band era, saxophones and trumpets were all the rage. The guitar took over in the late 1960s. We still do a large amount of traditional music, but technology also plays a huge part."

Like his father Patrick, Niall combined college with working part-time in the business, learning from the bottom up. He's a versatile musician, plays fiddle, piano and tin whistle and rarely misses his Wednesday evening sessions.

Much of the edge which Waltons has retained over its competitors is due to the expertise of its 105 employees, most of whom are trained musicians, says Niall.

Expanding the manufacturing side of the company and establishing its own recording label was undoubtedly a major factor in the company's growth - Waltons exports Irish-made bodhrans and tin whistles and sheet music to 18 countries.

Next January, Waltons is launching Urban Ethnic, an album by a newly-formed group called Rinka which celebrates the multi-culturalism that has transformed the traditional Dublin music scene.

The school of music, run by Niall's sister Aideen and brother-in-law John Mardirosian, has 1,500 pupils studying everything from instruments to recording techniques.

With successful musicians such as Enya using home recording studios, the Waltons client list is impressive.

The only expansion outside the music industry was in response to the need to put its valuable North Frederick Street premises to better use. Warehousing, manufacturing and head offices were transferred to a 13,000 sq ft block in Blanchardstown.

In partnership with hotelier Fionn MacCumhaill, 28,000 sq ft of old Georgian buildings surrounding the city shop were refurbished and converted into a 50-bedroom hotel.

"The more music shops the better," is Niall's response to competition in what is a fairly specialised market.

"I don't think the multiples can kill any good business that's doing its job well. Music is such a specialised industry where people want product knowledge.

"My grandfather's motto was to try and sell the best instrument people can afford, not to extract money but to give them the best opportunity to play."