Vague, Subjective Guide to Obvious Tango Orchestras

In no particular order, not even alphabetical, this a dump of my 100% subjective and fairly eccentric mental catalogue. In no way should this be taken as reliable or comprehensive.

Troilo
Sounds the most orchestral of all orchestras - the most like a symphony orchestra. If there seems to be a lot going on, with numerous different sounds having equal prominence, and at the same time it's all rather grand and maybe wants to be part of a larger work, it's probably Troilo. Also sounds like everybody, so if you know you know it, but can't think who it is, it's probably Troilo.

Di Sarli
I can't improve on Mike Lavocah's insight: Di Sarli does everything with the violins. Recorded over a long time with huge variations of style and sound and feeling, but the violins thing is consistent. Also sounds like Fresedo with a difficult girlfriend. Some of the late stuff sounds like Di Sarli trying to be Pugliese; with results that are kind of wonderful, if you can keep a straight face.

D'Arienzo
Sounds loud, even when playing quietly. Dense texture. Had Biagi at the piano for a lot of it, and sounds like Biagi without the holes. Some of the late stuff sounds not just intense, but completely bonkers, until you compare it with Biagi. The flesh and organs of tango.

Biagi
Sounds like D'Arienzo with holes in. A lighter texture, and not just intense, but genuinely eccentric. The offbeats are much more unexpected. Appears never to have recorded a bad or boring track. A truckload of amazing valses, not enough milongas. In the late recordings he doesn't fall into the trap of imitating Pugliese; he's influenced by changes of style, and grows, but remains his entirely genuine, electric, eccentric self.

Canaro
Kind of the backbone of tango, including the dodgy discs and the odd hernia, gunshot splinter or missing fortune. Always sounds totally professional, brisk, and organised. Best when there's a really strong tune and Maida singing. But recorded a lot, for a long time, and is very various.

Caló
Sounds glossy and dark. Salon in a dark suit. Tbh I can't describe it very well because are only a few tracks I like all that much, and most of those remind me of the JAWS theme. The ones that are good are magnificent.

Fresedo
Sounds like a 30's Hollywood movie involving palm trees and pineapple hats. Tuneful, romantic, often a bit sugary. Or like Di Sarli with a nicer girlfriend and fewer violins.

Laurenz
Sort of buzzy. Like dancing bees. The most famous tracks have Alberto Podesta doing the operatic tenor thing. When he flies, he still comes down at the right moment. Bermudez has a darker, lower voice. But the bees are still there.

Tanturi
Sounds kind of like teeny-tiny Troilo for a much smaller room. Still a lot going on, but more portably.

Pugliese
The sound of the orchestra itself, with or without the singer, is full of love. This is music of a bigger picture, but expressed for and by two humans in one embrace that embraces a whole world.  Pugliese is never caught up in narrow emotionality; but is deeply and satisfyingly real, like a plate of egg and chips. Pugliese was so influential that all the modern orchestras seem to be trying to sound like him, which is a trap better musicians than they are have also fallen into.

Rodriguez
Sounds like walking along very carefully, one step at a time, not stepping on the lines on the pavement, because of the bears. But either quite amiably tipsy, or, in some tracks, weeping drunk.

D'Agostino
Sauntering, episodic, and sounds a bit pissed off, or rambling drunk. Nice to play with when you're not going anywhere in particular. On reflection, I prefer the ones where Vargas comes in early and sings his thing, and the orchestra provides a fairly brisk, minimal frame otherwise.

De Angelis
Another kind of sauntering and episodic that wanders off in no particular direction and has a giant drama while staring at some random wall. Generally a bit art-movie. History's most annoying Cumparsita, which wurbles on for what seems like twenty minutes, is instantly forgotten, and then keeps coming back in your head for days.

Donato
Probably the one that sounds most like late 19th century opera that you can dance to. Like the Pearl Fishers or Tosca. Properly entertaining music, with loads of rhythm, super tunes, and the occasional quite good joke.

Demare
Lush (Mike Lavocah again). A gooey chocolate hazelnutty sort of sound with a trace of jazz. I love it.

Lomuto
Daaah-dum. Dark woodwind with a distinctive ending.

OTV (Orquesta Tipica Victor)
Victor studio house band: sounds incredibly professional and picked good songs. Wants to be driving scene music for a low-dialogue film.

I usually don't hear the opening of the first track and name the orchestra in my head, unless the track is a particular favourite or has a very distinctive opening: I usually just focus on how much I like it, and who I am most interested in dancing with, based on the general feeling it gives me. When I name the orchestra it's usually later, whether I'm dancing or not. This is why I get absolutely ropeable if the DJ plays their weakest track first in the tanda, or plays inconsistent tandas that don't carry through what the first track promised. Don't do it!