Interesting question, though every sentence could be a separate question, asking for detailed explanation and examples. I'll try to be concise.
"We have also sound-houses, where we practise and demonstrate all sounds, and their generation.
Equipment to play audio is widely available and portable. You can put on headphones and feel like you're in a concert hall. Concert halls are in turn equipped with audio devices.
We have harmonies which you have not, of quarter-sounds, and lesser slides of sounds.
Music developed greatly within last 400 years, we saw development of classical harmony, extended in romanticism, then jazz and contemporary music, and it's still developing.
12-tone scale is still basis for the mainstream western music. There are however multiple experiments which attempt to go beyond that.
Divers instruments of music likewise to you unknown, some sweeter than any you have, together with bells and rings that are dainty and sweet.
Real, electronic and virtual instruments keep being invented. Technology, in particular synthesis and sound processing technology allow to create new sounds, unheard before.
We represent small sounds as great and deep; likewise great sounds extenuate and sharp; we make divers tremblings and warblings of sounds, which in their original are entire.
Modern sound processing can alter the original signal greatly, including dynamic processing, distortion, modulation and spatial effects, infamous pitch correction and more...
We represent and imitate all articulate sounds and letters, and the voices and notes of beasts and birds.
Voice synthesis is widely available and used commercially to generate voice messages.
VOCALOID software is already used to replace lead vocalist in some music genres, though as of 2020 it still doesn't sound like a natural human voice.
Virtual instruments, including orchestral instruments, drums, basses and guitars are available commercially, used, and in many contexts indistinguishable from real instruments.
We have certain helps which set to the ear do further the hearing greatly.
Sound amplification plays this role. A small band can perform for tens of thousand of people. Another example: some classical guitarists performing with orchestra use slight electronic amplification, even when performing pieces from the times when such technology wasn't available.
We have also divers strange and artificial echoes, reflecting the voice many times, and as it were tossing it: and some that give back the voice louder than it came, some shriller, and some deeper;
See above, sound processing.
yea, some rendering the voice differing in the letters or articulate sound from that they receive.
Some modifications could be possible with classical sound processing (e.g. by cutting and swapping words or syllables, but it seems there is enormous potential in neural networks. We have already seen deep fake videos showing people saying things they haven't said in real, see e.g.
These are just first attempts to use the technology.
We have also means to convey sounds in trunks and pipes, in strange lines and distances."'
Sound recording technology, sending sound via internet, live concerts over internet, or even performing together with another musician over internet is possible. Or a simpler example, musicians can play in different rooms in a studio, hearing each other exclusively in headphones.
Predict the next 400 years, if you have a minute.
Good luck with predicting next 10 years ;) We're facing much faster technology progress than it was 400 years ago.
In particular, neural networks (NN) saw enormous development during the last decade, and the results in many fields are shocking, despite it's clearly just the beginning. These are some example applications in music technology:
- Neural DSP Quad Cortex is a commercially available guitar sound processor claiming to use NN to emulate sound of real devices (guitar amplifiers) in a way that is indistinguishable to human ear
- Tone Transfer is a project attempting to capture sound of an instrument basing on a recording sample, and allowing to play another instrument recording using that sound. https://sites.research.google/tonetransfer
- OpenAI Jukebox produced a fake recording based on Frank Sinatra recordings.
https://soundcloud.com/openai_audio/jukebox-265820820 (it's a bit scary in many senses...)
There are probably many more...