Well, I can't help with tomatoes but I can express my views. I put that caveat early on because that is what they are: I ought to say straightaway that there are many fine players who use plastic heads and like them. Timpani are quite a complicated instrument and there are many factors which come into producing a good sound. There is the shape, design and actual construction of the 'kettle' and again different players have different preferences and likes and dislikes for particular instruments (I guess the same with all drums).
There is also the question of mallet choice and design and lastly, but by no means leastly, the actual technique of an individual player and the grip that he or she uses. All these factors in producing good sound but all are personal preference and it could well be that a good player with a fine technique using mallets which they select (or make themselves) could produce as good a sound as a calf skin drum.
However, I agree that it will be a different sound and that difference is why I prefer calf skin heads which have a deep 'brown' sound and seem to me to be particularly at the two extremes of markings - pp and sf for example. I have heard players I know to be fine musicians struggle to get a really good sound at pp on plastic heads and equally they have a tendency (in my opinion) to break up at really loud volumes.
However, there is as much personal opinion about all this (bowl, skin, mallets, technique) as there are players and so I doubt a concensus would be possible.
Interestingly there is less divergence of opinion regarding symphonic Bass Drums where calf heads (so far as I know) are very much in the majority and there seems to be a fair body of opinion that plastic heads do not work nearly so well on this 'fixed tone' instrument.
The original poster's question about whether a roll from pp to whatever keeps in tune better is interesting but provided the calf skin player is happy with a true note at the start it shouldn't make any difference - save my view that plastic heads can break up a little at really high volume. I suspect this applies particular to the smaller drums and may be less of a problem on the 30/32 inch drum.
I'm afraid the Old Ladies are notoriously unforgiving of poor technique and immediately shout 'How DARE you' which I why I give mine names and talk to them all the time. Timpani are not for upsetting.
Related to that matter could I also point out that I suspect that because the timpani roll is a single stroke roll there may be a perception that it is easier to execute than the apparently more complicated ll-rr-ll-rr of the snare drum but that is not so. The size of the timpani membrane is such that you cannot bring down both sticks exactly together to sound a roll....one MUST be a grace note to give the drum the time to SOUND that first stroke a fraction before the second hits it. If you fail to do that you will 'muddy' the sound and there is no way once that sound pattern is established that you can correct it within the same roll.
That is not so with the snare drum: you can improve a 'ragged roll' very easily by increasing or diminishing beats etc, closing them up, opening them out. You have no such option on the timpani which is why I am always so polite to them.
A good test of a timpanist is the roll in the finale of Romeo and Juliet Overture (Tchaikovsky) or the apparently simple figures in the transition to the finale of Shostakovich Symphony No 1. If the former sounds as if at the end it is being played by Animal from the Muppets then something has gone badly wrong and the Shostakovich is a real challenge to the player for very simple reason that there are massive dynamic differences and you have no chance to change mallets. It's a one-size fits all situation and a great challenge to both mallet selection and 'touch' which matters so much with this instrument.
These irascible old ladies will once again say: 'How DARE you hit me like that' if you get it wrong....if you get it right I happen to think they are the greatest instruments in the symphonic orchestra capable of making - or breaking - a performance and if you disagree with that you might at least acknowledge that they can ELEVATE a performance.
As I have mentioned in another thread, I would nominate the second movement of the Deutsche Requiem by Brahms. I honestly believe the timpani MAKE that movement and it is as thrilling to play as it is to hear in a good performance. Truly wonderful writing for the instrument.
The original poster would be correct in assuming that all the world war II and immediate post war recordings are likely to be calf skin drums. Two of the best recordings and performances on the timpani that I have heard on recordings are both conducted by Furtwangler (who ENCOURAGED his timpanists
One is a public performance of Brahms Sym 2 (1945, I think) in which the timpani playing in the finale is nothing short of phenomenal and the other is a recording of the Pastoral Symphony (which I think was not well reviewed) and I believe this was a studio recording for EMI from about 1952 or 1953? The rolls in the Storm are equally phenomenal: remember these are single stroke rolls (and diminishing in volume) but you won't hear the 'single strokes' in this great performance. My view of the other instruments has no more validity than that of anyone else but I can say that this is great timpani playing. You just hear what Beethoven surely intended: the retreating sound of thunder as the storm moves elsewhere and leaves the rain dripping from the leaves: what a MAGICAL moment in music.
You don't hear single strokes in real thunder and you won't in this performance either. I think the whole playing is the best I have heard in this work (which is probably why critics didn't like it). I think it was the Vienna Philharmonic but am away from my LP's and cannot say for sure.
Either way, I play it again and again and I have never changed my view about it.
Great players abound today to delight us all but let us not forget that (in my opinion) great players have ALWAYS been around for every instrument.
PS: Neither the Brahms 2 or the Pastoral performance sound like plastic heads to this Old Chap.
Kind regards, Alan M. Watkins
