This topic it is of upmost importance to me in this stage of personal development, if I understood you. After my obsession with timbre, when I finally got a bit of satisfaction with violins, after horns, I failed with tempo. Or with inner tempo. The playback, digital, FIR filter, then plain solid state ancillaries afterwards, solid, basic, simple, is out of doubt (it failed me with other issues but not this one). When I used a pro monitor the flexibility with tempo that performers used to create meaning in certain pieces disappeared. My first encounter was with Brahms first piano concerto. Some interpretations are virtuosistic, some subtle, some strong, colourful, singing, dramatic, but at the end, very homogeneous in their approach, like the soloist decided what is about and play with a single idea. But few of them play with that propulsion and alternance of mood of a young man in loved without hope, but with reasons to dream with happiness, with desperation, dark moments and joy, in and out.
Then Beethoven violin concerto, more successful for me in good interpretations but a few like a drone sound with a first movement like in a loop with no end.
Then Sibelius violin concerto...
With the pro monitor not very well powered by the amplifier, the tempo flattens, there are no perceived nuances that I know are in the recording, nuances with the tempo. I can not perceive them. The drama disappears, and some other feeling, uncomfortable takes place: impatience. I want more impulse, more speed, more and more speed, more sounds at the same time, more instruments, more musical noises, more cacophony, more events in the sound per second. I was getting bored but in a strange way.
I knew about the recordings in a previous set up with the same system and a mid band centric monitor, with tough diaphragm but no bass like at all. The nuances with tempo were there, in fact I learnt about them with this system. Then, finally, I got another monitor, underpowered as well, but capable of too much drama. So much so that it amplifies a notch all those nuances, more obvious now than ever. And more useful range.
And everything was well until I discovered what I lost in return. Per Nørgård, and his third symphony, Gorecki, Unsuk Chin, Birtwistle, ... Back until Schoenberg. All this music was meaningful, enjoyable, explorable, with the pro audio monitor that probably was made not for music rendering but for sounds of any kind, like water drops, metal banging and whatnot. At the moment I can’t go further in my research of this topic. I don’t have the time or means.
Some Mahler, not romantic, made more sense, like the first of the modernist. One recording, with Sibelius and Schoenberg violin concertos was night and day. You have to change speaker to enjoy each. I don’t have any insight why it is happening. The superb drama queen monitor, neutral, subtle, underpowered, can perform like a diva. But with xx century music later than Strauss or some later romantics, it is impossible. Any composition, modern, with a clear indication, rigid, of tempo, from the composer, like it is part of the texture of the things, it is dead music. Or music performed by people with technique but not interest, like only playing until the end to get a cheque and run away fast from there. But it is not like that with the pro monitor.
From Bach to Wagner, to maybe Rimsky-Korsakov and Falla, Albeniz, Rodrigo... the diva take you to a place like you grasp everything, like a omnipotent god (Beethoven is like that)
I don’t know which elements are interplaying here. At some point I thought about modern manipulation of sound in compositions that use water, stones, buckets, helicopters, guns, cups and other objects, as part of the music-making sounds. Or exotic Indian, Balinese, Chinese, Japanese,... instruments interleaved with Center European sounds of a orchestra. I thought, in my obsession with timbre, that my problem, my perception, was again new timbres not being accurately rendered. And that the pro monitor can do a good service here. Even if it flattens the tempo of Xix century Music and the violins are a metal instrument that consists on scratching with your nails a blackboard.
But I know it is not the truth. I carry on thinking and exploring solutions. Regarding Romy wider tempo manipulations, in the hands of conductors, maybe, or as a phenomenon that emerges as a group of individuals doing it in their own terms, it is absolutely out of my reach.