WHEN he is on peak form, the Ukrainian virtuoso Yuri Bashmet is the most charismatic string soloist in the world - an amazing fact, when you consider that he plays the viola.
But then the hitherto humble viola has been coming out of its shell in recent years and Bashmet, for all his flair, is only the most prominent of a remarkable crop of solo violists.
If you go to a concert by the Japanese player Nobuko Imai, you are sure of a fine performance. The same goes for the Americans Kim Kashkashian and Paul Neubauer; the Norwegian Lars Anders Tomter; the Germans Tabea Zimmermann, Wolfram Christ and Hartmut Lindemann; or Bashmet's remarkable compatriot Michael Kugel, now based in Belgium.
Yet Bashmet, with his 1960s hairstyle and air of an ageing rocker, is the man the young people flock to hear - and at a time when orchestras and impresarios are worried about future audiences, that is a big plus.
My own early memories of him in the Queen Elizabeth Hall in London are indelible. I first heard him in 1978, when the Soviet authorities would not allow him out except to play Mozart's great Sinfonia Concertante with the violinist Vladimir Spivakov.
In a particularly well-cut dress-suit, and with his hair relatively short in those days, he looked rather like a reincarnation of Paganini and played like one (the recording of the Mozart which he and Spivakov made in July, 1979 is now on the Royal Classics label).
I next encountered Bashmet 10 years later, when he came as a recitalist to the Lionel Tertis International Viola Competition (held in honour of the first great violist of modern times) on the Isle of Man.
He and his superb pianist, Mikhail Muntian, arrived only an hour or two before the recital and I earwigged on their brief rehearsal, along with the violist Martin Outram of the Maggini Quartet.
Cigarette hanging from one corner of his mouth, the now longhaired Bashmet stood nonchalantly just behind Muntian, reading the music over his shoulder.
He was running through five little dances by Marin Marais which many violists play. But within seconds Outram and I were looking at each other in disbelief, our lower jaws on our chests. For sheer rhythmic elan, ease of tonal projection and clarity of articulation, neither of us had heard anything like it from a viola player.
The astonishing thing I discovered a day or so later was that although Bashmet had a good instrument, a 1790 Carlo Testore, he used a cheap bow which most players would not give a second look.
Made of brazilwood rather than the usual pernambuco, and with tawdry fittings, this bow came apart during Bashmet's stay on the island and the competition's resident luthier, Wilfred Saunders, made a temporary repair by whipping on some twine.
When I next met Bashmet a year or so later, he had not bothered to have the bow properly repaired and the twine was still in place. As far as I know, he is still using that bow.
This casual side of him has occasionally been the despair of concert organisers. The Danish Radio Symphony Orchestra has publicly said it will never engage Bashmet again, because his performance of a new concerto by Poul Ruders was not up to par - to add insult to injury, he was in Copenhagen to receive an award at the time!
Members of the little string orchestra which he founded in 1986 rebelled against him and he has had to gather together a new collection of Moscow soloists.
On the other hand, Bashmet has clearly been making an effort in recent years to behave more responsibly. He has been a success as chairman of the Tertis Competition and has successfully run his own competition in Moscow.
But within him will always be the boy who switched from violin to viola at 14 because he was more interested in playing the guitar and thought the viola would give him an easier ride.
Born in 1953 at Rostov in the Ukraine, Yuri Bashmet moved with his family to Lvov when he was five. He first started learning the piano and at eight took up the violin. "My mother decided to put me in music to do something," he told me in his idiosyncratic English, implying that he was a bit of a tearaway as a lad.
He clearly had an excellent teacher in Zoya Zertsalova but between the age of 12 and 18 he was more interested in the rock band he led in Lvov (his elder brother Yevgeni still plays the guitar). "When I was 12 years old, it was the time to be interested in The Beatles," he says. "We could get their records in the Soviet Union and there was no one else as interesting musically except perhaps Blood, Sweat and Tears in Chicago."
At 18, having distinguished himself on the viola despite his laid-back approach, he was sent to the Moscow Conservatory, where he had two years with Vadim Borisovsky, who trained generations of superb Soviet violists. When Borisovsky died, his ege protege (and successor in the famed Beethoven Quartet) Feodor Druzhinin took Bashmet on.
The 1976 Munich competition, which he won, not only made Bashmet known in the West but also brought him together with Muntian, a wonderful accompanist who has his own footnote in musical history because he gave the premiere of Shostakovich's last work, the Viola Sonata, with its dedicatee Druzhinin.
Bashmet names his influences as Druzhinin, the violinists David Oistrakh, Viktor Tretyakov and Spivakov and the cellist Natalia Gutman. He became part of a close-knit group which also included Gutman's husband, the violinist Oleg Kagan, and the pianist Svyatoslav Richter - who picked him out as a recital partner when he was still a student.
The death of Kagan in his 40s from cancer hit Bashmet hard and the more recent death of Richter - although less unexpected - was another blow.
With Tretyakov he has recently made a beautiful recording for RCA of the little double concerto by Max Bruch and all the signs are that as he moves into his late 40s, Yuri Bashmet is finally coming of age.
HE is an awesome virtuoso when on song. His right arm executes a dazzling array of bow strokes, while his left hand delivers pinpoint tuning. He is a magical interpreter of such difficult works as the Shostakovich Sonata, the early Hindemith Sonata and Britten's Lachrymae (all of which he has recorded live with Richter and in the studio with Muntian).
He and Muntian will be playing the Hindemith and Britten in their recital on Tuesday and I am sorry I shall not be there to hear their interpretation of Beethoven's Notturno - an arrangement of the early string trio, Serenade, Op 8.
If the audience in the National Concert Hall is lucky, the duo will treat them to a favourite encore, an arrangement of Stravinsky's sardonic Russian Song from his opera Mavra. One thing is certain: the performance will not be boring.
Yuri Bashmet will perform with Mikhail Muntian on Tuesday at the NCH, in The Irish Times Celebrity Concert series.