You can do X-Y on almost all old analog scopes and get Lissajous figures (really cool) which some folks use to get phase measurements. You can align you analog stereo so that both channels are "in phase" if you care about that sort of thing.
Dig scopes dont do X Y easily.
Sure they do. I don't know of a DSO without an XY mode.
He said easily. While almost any digital scope will have an X Y mode, my experience with trying to use it is that it is invariably crappy. Also digital scopes don't have a Z input like many analog scopes do, which limits you to the less interesting uses of X Y mode.
My MSOX3000T has Z mode. It is not real Z mode (fully analog) but more of a blanking circuit (with adjustable level). Still much better than none. There are (where) some Tektronix TDS3000B/C series where you had full X-Y-Z (also Z for blanking) and you could show video picture...
I guess nobody cares anymore ..
Using X-Y to measure phase is something that will work even with crappiest digital scope. You cannot do good scope art, but Lissajous figures are just fine.
Many people just don't know how to set it up.
For instance, you need to enable hi res mode to lower the noise. Signal is very low in frequency anyways. And you need to play a bit with time base. But you can get very usable results for just looking at Lissajous patterns.
Scope art, for that you need analog scope.
You can also use the phase measurements on scopes that have it. Or if you just want signals in phase, you just overlap traces on top of each other and move things around until they overlap. If we exclude electronics (filters and delay inducing elements) only source of audible phase difference is physical placement of speakers, microphones and listener's ears.
In which case you might not want to measure phase delay, but a physical time delay (time of arrival) in normal timebase.
You can also do many things you cannot to with analog scopes. Capture single pulse and then freeze it.
For audio work, a cheap digital scope and USB sound card and software will give you fantastic capabilities. Or Analog Discovery, that is a electronics laboratory in a small box.
Of course, that is all more than 200 USD.
OTOH for 200 USD you won't get much, however you look at it. Analog CRT or DSO.
For just looking at the signal shape even those handheld gizmos are good enough for audio range.
Old analog scopes are either nostalgia and familiarity (after 30 years, they feel like old friends), sometimes better specs for niche things (like scope art), or sheer coolness of old CRT "ping machines".
But make no mistakes, you will not have only one in the end (one working and multiple parts donors), it will cost you much more money than a new modern decent 500-1000 USD DSO in a long run and they will be a project for themselves most of the time.
People have them and keep them same as an oldtimer cars. If you are doing it on purpose, are prepared to work on them and spend money on repairs, they are good fun.
If you really set your heart on analog scope, I wish you good luck hunting for one that works well and won't give you problems.