Baystruments - I had two tgstation forks for some reason and had to delete one and that nuked the last PR (#51459)

Instruments and sound channels refactor.

code/controllers/subsystem/processing/instruments.dm

@@ -0,0 +1,56 @@
+PROCESSING_SUBSYSTEM_DEF(instruments)
+	name = "Instruments"
+	wait = 0.5
+	init_order = INIT_ORDER_INSTRUMENTS
+	flags = SS_KEEP_TIMING
+	priority = FIRE_PRIORITY_INSTRUMENTS
+	/// List of all instrument data, associative id = datum
+	var/static/list/datum/instrument/instrument_data = list()
+	/// List of all song datums.
+	var/static/list/datum/song/songs = list()
+	/// Max lines in songs
+	var/static/musician_maxlines = 600
+	/// Max characters per line in songs
+	var/static/musician_maxlinechars = 300
+	/// Deciseconds between hearchecks. Too high and instruments seem to lag when people are moving around in terms of who can hear it. Too low and the server lags from this.
+	var/static/musician_hearcheck_mindelay = 5
+	/// Maximum instrument channels total instruments are allowed to use. This is so you don't have instruments deadlocking all sound channels.
+	var/static/max_instrument_channels = MAX_INSTRUMENT_CHANNELS
+	/// Current number of channels allocated for instruments
+	var/static/current_instrument_channels = 0
+	/// Single cached list for synthesizer instrument ids, so you don't have to have a new list with every synthesizer.
+	var/static/list/synthesizer_instrument_ids
+
+/datum/controller/subsystem/processing/instruments/Initialize()
+	initialize_instrument_data()
+	synthesizer_instrument_ids = get_allowed_instrument_ids()
+	return ..()
+
+/datum/controller/subsystem/processing/instruments/proc/on_song_new(datum/song/S)
+	songs += S
+
+/datum/controller/subsystem/processing/instruments/proc/on_song_del(datum/song/S)
+	songs -= S
+
+/datum/controller/subsystem/processing/instruments/proc/initialize_instrument_data()
+	for(var/path in subtypesof(/datum/instrument))
+		var/datum/instrument/I = path
+		if(initial(I.abstract_type) == path)
+			continue
+		I = new path
+		I.Initialize()
+		if(!I.id)
+			qdel(I)
+			continue
+		instrument_data[I.id] = I
+		CHECK_TICK
+
+/datum/controller/subsystem/processing/instruments/proc/get_instrument(id_or_path)
+	return instrument_data["[id_or_path]"]
+
+/datum/controller/subsystem/processing/instruments/proc/reserve_instrument_channel(datum/instrument/I)
+	if(current_instrument_channels > max_instrument_channels)
+		return
+	. = SSsounds.reserve_sound_channel(I)
+	if(!isnull(.))
+		current_instrument_channels++