My, how things change. Or, rather, how they appear to change. Last week, I reeled out of a concert performance at the Perth Festival given by the four-strong Palladian Ensemble. On paper, it looked a dry, esoteric affair, possibly of interest only to those curious about the arcane tributaries of what is now called "historically informed" performance.

In fact, the performances I heard, of Baroque music by Bach, Marin Marais and JeanBaptiste Antoine, were magnetic, not least because of the quality of playing by the musicians : recorder player Pamela Thorby, violinist Rodolfo Richter, guitarist William Carter and viola da gamba player Susanne Heinrich.

The dazzling virtuosity of Thorby and Richter in the many dialogues and interchanges in the course of their performance, was staggering. The dead-centre accuracy and soulful playing in what we might call the engine room of the music, the guitar and gamba, was breathtaking and moving. It occurred to me that if this had been rhetorical, highly charged, Romantic music of a later century, rather than intimately discreet music of the Baroque period, the musicians who unleashed these levels of expertise and acrobatic skill would be regarded as superstars.

It also struck me just how far we have progressed in terms of what used to be called period instrument, or authentic performance. Does anybody remember back 30 years to some of the earlier efforts to capture and portray the music of composers from Bach, and before to Haydn and Mozart, on instruments and in a style appropriate to the period?

Does anybody remember the excruciating nasal whine of a period oboe? Or the castrated cat-like yelping of a period violin in the hands of somebody who hadn't quite mastered it, the delinquent instability of its tuning, or the shortphrased articulation of an appropriate style of playing? And what of those natural horns, with their yards of detachable plumbing, whose behaviour was unpredictable and whose strangulated sounds suggested the player had inadvertently swallowed the mouthpiece?

Why were we all so polite about the dreadful sound of music that seemed to be associated with dusty academe? Was it because it was worthy and a genuinely interesting attempt to find out what the music of Bach, Mozart et al actually sounded like in their time and on instruments of their period, as opposed to the sleek, glossy reproductions of their music on polished, modern instruments?

I guess that was the case. I remain curious, however, about our critical silence during the developmental days of the period instrument movement. Why didn't we just say: excuse me, we understand what you're trying to do but this hellish noise can bear little resemblance to the composer's intentions, however limited the contemporary instruments might have been.

Maybe we didn't want to seem ignorant. Our muted, uncritical support was unnecessary and wrong-headed. There had, after all, been a number of striking early developments in the "movement" which had established benchmarks for quality. As long ago as 1966, John Eliot Gardiner founded his Monteverdi Choir (to be joined, two years later, by the orchestra). They had a seminal impact on technical accuracy and stylistic veracity.

Christopher Hogwood's Academy of Ancient Music was founded in 1973 and their work in "authentic" performance, especially in a groundbreaking series of Mozart symphony recordings, had a huge impact. Before them all, of course, the veteran Nikolaus Harnoncourt had founded his pioneering group, the Concentus Musicus Wien as long ago as 1953, while Harnoncourt was still a cellist in the Vienna Symphony Orchestra.

In other words, there was plenty of evidence the real musicians in the movement were on to something worth discovering, which would be attitude-changing. Maybe we just didn't listen closely enough, or dare to draw lessons from those pioneers.

Time has marched on, historically informed performances by period instrument orchestras and ensembles have proliferated, their influence has been enormous and they have developed predatory appetites for areas of the repertoire, which, 30 years ago, would have been unthinkable. We take their playing standards for granted now and it's only when a world-class performance, such as the one I experienced last week from the Palladian Ensemble gives you a jolt, that you think: My God. Just 30 years ago, this was unimaginable.

I'm off now for a bit of brand old Bach.