The period performance revolution is now very mature. Some of the earliest early music groups have been going for some considerable time (Academy of Ancient Music:35 years, Concentus Musicus Wien:50 years). In fact the ideas that arose from these experiments have now percolated out to the standard orchestras. Conductors like Nikolaus Harnoncourt, Roger Norrington and Charles Mackerras regularly work with non-period orchestra and create remarkable syntheses. In fact Mackerras, for one, seems to prefer working in period practice with a modern instrument orchestra, though he often makes modifications like using narrow bore trombones.
It is not only mainstream orchestras who have taken on board period practice. The younger generation of singers routinely move between modern and period performance. Opera houses now regularly use period performance specialists to conduct baroque operas, often with a period band and expect young singers to fit in. The young conductor Emanuelle Haim regularly works with young mainstream opera singers within her period group Les Concerts d'Astree.
This is certainly all very creditable and impressive. But what it has disguised is the fact that in all period performance, we are using old instruments and techniques with modern voices. There are a few groups like the Consort of Musicke where both the singers and instrumentalists perform using identical period style. Perhaps in the area of small to medium size groups this is more common. But I doubt that few of us have heard an Italian baroque opera where all the singers performed using identical period style to the instrumentalists, i.e. we hear real period voices.
You might argue that we do not know what period voices sound like, but 40 years ago the same was true of instrumentalists. It was only by experiment and exploration that the early period practice performers developed.
To take a concrete example. In Handel's day, one of the most admired 'tricks' was the Messa di Voce, the taking of the voice gradually and smoothly from quiet to loud and back again. This was something that castrato Senesino specialised in and expected to be able to do in his arias. Few singers nowadays seem to study this, certainly I have heard very few Handel operas where the singers have the sort of control and technique to do this, other vocal techniques have become more important. This is not to say that modern performances are bad, just different, using different vocal techniques.
This leads to a one-size fits all sort of technique, where a singer will use similar ways of singing elaborate passage-work in Handel and Rossini. I have a problem with some popular singers because, to my ears, their singing of runs in Handel sounds too much like the way they'd sing Rossini. I know from discussions that this does not bother other people, in fact they find my ideal Handel performance somewhat unsatisfactory. This is a matter of educating our ears, a process that early music groups had to go through all those years ago. Unfortunately not that many groups seem to be doing this with baroque opera and large scale vocal performance.
Consider Handel oratorios, we know little about the minutiae of their first performances. But it is generally agreed (I think) that he used a choir of men and boys but had adult soloists. A number of commentators say that the soloists sang in the choruses but I am not aware that anyone has tried this. Does it work, I wonder? What does this possibility say about the relative differences or similarities of the vocal techniques of the female soloists and the boys?
One area where these sort of experiments have been taking place is with Bach performance practice. The first baroque period practice performances tended to use a one-size fits all group of performers so that Bach's passions were performed by similar groups to Handel's oratorios. We are only now beginning to accept that Bach's performances might have used 1 singer to a part. But even so, we are hearing Bach performance practice sung by modern voices and modern vocal techniques.
These concerns covers not just Baroque performance. It even affects Wagner and this example is illuminating because recordings can help point the change in vocal techniques over the 20th century. We are now only just experiencing occasional Wagner operas with period orchestra. But regarding singers the gap between modern and 19th century vocal performance is huge. There are big issues of vibrato, spread and focus, besides the changes in the way vocal technique is taught. You only have to listen to pre-war recordings to realise that singers had far more focussed voices, less width more penetration. This means a lot when it comes to how the voice carries over Wagner's large orchestra and also, how fast the speeds could be. The role of Brünnhilde in Die Walküre is written with trills; most modern Wagner sopranos simply don't have voices built for trills, in fact one or 2 have so much vibrato as to render a trill obsolete.
As a final example of the changes to voice types I mention 2 extreme performances. At the urging of tenor Jean de Reske (who sang both Italian opera and Wagner) soprano Nellie Melba tried singing Brünnhilde in Die Walküre at the Met. Similarly Isobel Bailey was persuaded to sing in a live broadcast of Act 2 of Tristan. Neither performance was successful, but the fact that they were attempted tells us a lot about what it was though such voices could do and what sort of voices might have been singing in Wagner.
In fact, I heard Bailey singing when she was in her 80's. Her voice was still remarkable, pure, accurate, focussed. The closest modern singer is Emma Kirkby. And whilst there are one or two 19th century operatic roles that I could imagine Dame Emma doing, Isolde is not one of them.
So that I do not end on a low note, I'd like to highlight one area where the singers have worked closely with the instrumentalists, notably French baroque music. Here William Christie and Les Arts Florissants have rediscovered the vocal techniques and the voices types necessary to correctly articulate French Baroque works. The work Christie and his group have put in has
enabled us to re-discover and entire world. I have a disc from the 1950's where Nicolai Gedda and Victoria de los Angeles sing excerpts from French Baroque opera. The result is fascinating, but entirely fails to illustrate the greatness of the music in the way that Christie and his group do. This shows how research into performance practice, vocal types and vocal techniques can illuminate our knowledge of the music itself.