The Beatles are about as Mod as Marilyn Manson is Goth, which is to say that if you were one before x-band got ridiculously popular, or completely independent of said band, you’re at least 90% less likely to consider the band to be at all related to your subculture than an outsider would assume. On the other hand, if said band was your gateway to the subculture, chances are far more likely that even if you no longer think they’re necessarily of the subculture, you’ll probably think they’re still important to the subculture, if only as, well, a gateway. You know, they’re kind of a misunderstood caricature of each subculture that’s ironically gained a modicum of credibility cos, well, kids and stuff.
The answer to “What’s the difference between a Mod and a trad skin?” and “What’s the difference between a trad goth and a romantigoth?” are the same: At least two stone to the latter, with an optional addition of ten years, and/or less hair for the gents. The implication of the joke is “when you’re young and / or slim, you’re the former, and then you age into the latter.” This is usually tongue-in-cheek, even though it generally speaks to an assumed-to-be-acceptable amount of sizeism and ageism in both scenes.
Where the overculture’s caricatures of punk and hippie subcultures are, generally speaking, more accurate than inaccurate (feel free to disagree, but I speak from experience), the overculture’s caricatures of Mods and Goths are, generally speaking, more inaccurate than accurate (again, feel free to disagree…) Where punks and hippies generally ignore the stereotypes, Mods and Goths seldom do, but will generally regard the stereotyping disdainfully when outside subcultural spaces (seriously, watch an outsider ask a Mod about the Austin Powers films, or ask a Goth about Fairuza Balk’s character in The Craft), but will laugh at it amongst themselves.
It’s fairly easy to break up each subculture into several “types”. It’s also easy to compare the Mod/Skinhead division to the Goth/Industrial (or Rivethead) division. Both divisions happened fairly early on, and it is generally fairly easy for one from X-side to move back-and-forth between that and Y-side; it’s also not as easy as some would like to believe to pinpoint the exact year or band/musician that sparked the division, though some hypotheses (1969, or Symarip’s “Skinhead Moonstomp”, etc…; 1980, Genesis P-Orridge, etc…) are certainly more popular than others. To the untrained eye and / or the unaware outsider, it might be difficult to tell the differences between a Mod and Skinhead or between a Goth and Rivethead, and there are more than enough “insiders” who really stopped giving a fuck about compartmentalising everyone at the clubs years ago, because it’s really not as important as some people might want to believe.
Generally speaking, racism and queerphobia is considered fundamentally antithetical to both subcultures, and it’s actually pretty damned easy to point to examples in the history of each subculture to support this fact, if you actually understand the histories, but every so often, you run into some person or another, and let me tell you, Internet….
And as I’ve said before, there is a clear and noticeable trend of Goths “ageing into” Mods. To be fair, though, some age into Rockabilly or revival Teds —but to be fair, I have it on good authority that the animosity between Mods and Rockers was blown WAY out of proportion by the press. And some shoegaze bands, especially Joy Division and The Smiths, are honestly equally popular among both subcultures, and it’s easy to find people in each cult that will point to Morrissey or Ian Curtis and say “obviously, this man is one of our own”.