AROUND 50 years ago, a revolution began in the world of classical music. Everyone has their own perception of how and when it began, based on when it impacted on them. My own experience is clear: it erupted at me in the early seventies with a raw blast of brass and the irritating buzz of crumhorns. This was David Munrow’s Early Music Consort, thundering out the music of Susato and others from the 16th and 17th centuries.

It quickly became apparent that the early-music brigade was on about more than merely unearthing unknown music from unfamiliar eras. They were addressing concepts about how music from any era should sound. What did Beethoven’s music actually sound like in 1800? What were the instruments like then? They were very different: today’s symphony orchestra is like a Rolls-Royce compared to the Model T resources available to Mozart, Beethoven and all the others. And the techniques of playing the instruments were different in every department from strings to woodwind to brass. The very instruments themselves were different: some, now shiny metal, were made of wood; violin strings, now made of steel, for durability, power and projection, were made from gut. And how, on these historic instruments, was the music articulated? Not as it is today, that’s for sure. And what about the basic tempos that the composers of centuries ago intended for their music? How did Mozart hear, in his mind’s ear, what his symphonies and concertos sounded like? And at what speed did he want his music to travel?

In every dimension, from accent to articulation, from parsing to phrasing, the music was different in its performance: could that be recreated, to the benefit and edification of today’s music-loving listeners, today’s musicians, to the composer’s intentions and indeed to the integrity of the music itself?

While the archaeological work was going on, issues were emerging and being addressed. Some of the playing sounded awful: strings sounded like cats being castrated; woodwind cracked and clucked like ducks with indigestion; brass brayed like constipated camels. Musicians would have to re-think and re-learn everything about their craft. Specialist directors took the "new" old music by the scruff of the neck. Christopher Hogwood, an original member of Munrow’s Early Music Consort, went off, founded the Academy of Ancient Music and set about recording all of Mozart’s Symphonies in boxed sets: the sheer differences were shocking and revealing in every dimension. John Eliot Gardiner went about changing everything in what seemed a ruthless quest for perfection. The movement grew up and got itself established. Standards developed and the quality went through the roof. Chamber orchestras excelled, but even symphony orchestras came on board: some will remember Sir Roger Norrington visiting the RSNO, and even running practical masterclasses in the "new" playing style. The musicians were very excited. It was a global phenomenon. It got itself a posh new Sunday name of Historically-Informed Performance and now it is very hip to be involved in HIP. And it rolls on, with countless tributaries and ramifications. Out of this revolution, which has had a colossal impact on the specialist training sector, new stars, individuals, groups and orchestras have emerged.

And one of the most-acclaimed among such groups is the string quartet, Quatuor Mosaiques, which, with pianist Susan Tomes, will have an exclusive UK residency next weekend in Perth Concert Hall where, between Friday 12 and Sunday 14, they will give four concerts featuring all six of Mozart’s so-called Haydn Quartets, dedicated by Mozart to the great inventor, innovator and musical pragmatist, Josef Haydn.