THEY USED to call him Boring Bernard. And despite a not-so- boring career in musical charge of the Concertgebouw, the LPO, Glyndebourne and Covent Garden - any one of which would be enough for some conductors deemed of interest - the nickname stuck. Never a showman, never big with talk or gesture, Bernard Haitink built his reputation out of conscientious craft rather than charismatic glamour.

But glamorous or not, Haitink has reached the very peak of his profession, universally admired. Audiences have come to realise that beneath that sober, strait-laced manner lies a true, expressive heart. Orchestras value his ability to make sense of a score, to grasp its structure as well as its detail. And I was surprised to learn (from somebody in the BBC) the other day that he is the conductor most players in the BBCSO consider their dream-candidate to succeed Andrew Davis. Not that they'd ever get him, given the modern bias of the BBCSO repertoire.

But there's another British orchestra unexpectedly sniffing around Haitink, if you'll pardon the expression, that might well get him some time in the future. The LSO. And this week it engaged him for a three-concert series at the Barbican which was remarkable for many reasons: not least in being the first time Haitink and the LSO have ever worked together. In the past, they've kept their distance, probably for good reason given the orchestra's thrusting Americophile temperament and Haitink's Dutch reticence. There wouldn't have been an easy meeting of minds. But positions have shifted on both sides. As the LSO has returned its attention toward Europe, Haitink has been opening up to America, courtesy of his recent appointment as Principal Guest of the Boston Symphony. The time for some kind of rapprochement has arrived. And it came pretty decisively on Sunday night, when the series opened with performances of genuine stature: textbook syntheses of impact and refinement.

Starting small with Haydn's Symphony No 86 - a fresh, well-balanced reclamation of territory all but surrendered these days to period bands - it finished big with Bruckner's 7th. And while Haitink isn't the most visionary Brucknerian, he certainly knows how to manipulate the composer's grand, deliberate cyclic processes. Structural sense was such a given of the reading that it came through naturally: not competing with the detail, and providing a performance where you saw the wood and the trees with equal clarity.

It was also, I should add for the record, a performance in which Haitink's feet were seen to leave the floor at one point, and by several inches. This was radical, and begged some questions. Has someone in Boston been taking him to a Men's Group? Will his Mahler now come tear-streaked? And will the LSO now be adding the artist formerly known as Boring Bernard to its own list of dream candidates for future jobs? I think I know the answer to the last one. It'll be definite, resounding yes.

If you go to the Barbican today you'll catch the final concerts in a BBC weekend devoted to the Czech composer Bohuslav Martinu - and more of that next time. But earlier in the week, the neighbouring Guildhall School staged a prefatory Martinu minifest of its own, including a double bill of pieces which have never been done in Britain before: a ballet called The Strangler, and the one-act opera Ariane. Their previous absence from the British stage isn't surprising. Martinu was tirelessly prolific, and his 400 published works include no less than 14 operas and 11 ballets with collective leanings toward French neoclassicism that strike the ear as chic but thin. The Strangler (written in 1948 for wind ensemble, piano and percussion with declaimed narrations) and Ariane (written 10 years later for larger forces) are typical examples: sub-Stravinskian retellings of classical legends, done with chilly, neoclassical detachment and an element of bogus ritual.

But one thing to be said for these Martinu tasters is that they were very stylishly done, in stagings by Stephen Medcalf which were basic, but worked minor miracles with shadow-projections and simple, good ideas. The dancing in The Strangler was attractive. Ariane had an impressive student baritone, Mark Stone. And the Guildhall Sinfonia under Clive Timms made out an arguable case for both scores as exotic curiosities.

But not as exotic, or as curious, as the Gamelan. Until this week I knew very little about the gamelan, except that it was the source of alluring oriental processes, suitably westernised, in works like Britten's Prince of the Pagodas, and that there used to be a complete gamelan orchestra displayed in one of the transparent, Thames-side rooms of the Festival Hall. Not long ago it vanished, and I assumed it must have been shipped back to Indonesia. But no. It's just been relocated to the basement, where apparently it causes less disturbance to diners in the RFH restaurant (good to know where the Hall's priorities lie these days), and where gamelan workshops take place on a regular basis.

Last week I went to one, and it was the most fascinating two hours I've spent in ages. I learnt how the orchestra is constructed - in layers of instruments whose function is related to their pitch, rather like the layered bells of Russian music. At the bottom, moving slowly, are the gongs that punctuate the phrase. Above them, moving faster, come mid-pitched metallophones (a sort of xylophone with extra resonance) that play the core, repeating melody. And above them, moving faster still, are higher- pitched metallophones that decorate the melody, bouncing off the beat and usually in anticipation of it.

I also learnt the fundamental rhythmic trick that makes gamelan music so engagingly different from anything in the West. Western music is generally governed by the first beat of a phrase, but gamelan is governed by the last - which is when the deepest, most resonant gong enters with a single pitch that (a) sounds gloriously "wrong" to a Western ear, however many times it comes around, and (b) ensures you don't even notice the first beat of the phrase that follows.

Seduced by this discovery, I spent the rest of the workshop pounding out a minimalist five-note phrase on my metallophone in mindless bliss, and realised why, of the 40 gamelan sets that exist in this country, one is owned by Glasgow Social Services. The floating, displaced rhythms of the gamelan work like a healing balm on troubled souls. And at pounds 6 for a session in the Festival Hall basement, they come cheaper than therapy.

Martinu: Barbican, EC2 (0171 638 8891), today. Gamelan workshops: RFH, SE1 (0171 928 0848).