There's also also the interpretation that the rich male is actually a deluded rapist who believes that they are in love. The rape angle seems to make sense, but the leaving her for being pregnant fits in well with the theory that "We Both Go Down Together" and "Lesley Anne Levine" are interlinked. Possibly it's a bit of both.
"O Valencia", on the other hand, is spot-on for this trope; in fact, the first bit almost seems lifted from Romeo and Juliet: A young mobster (probably son of the Don/Boss/whathaveyou) falls in love with Valencia, the daughter of a rival Don; her sister rats on them; her brother confronts them; Valencia runs to her lover's side just as her brother is shooting, and gets hit instead; she dies in her lover's arms; the lover decides to go on a Roaring Rampage of Revenge.
The song "Barricade" by Stars is occasionally, and erroneously, taken to be about a pair of revolutionary lovers who are torn away from each other by The Man. It's actually about a pair of violent football hooligans who are only being kept apart by the fact that one of them grows up and gets a job while the other stays a shiftless thug. Members of the band are somewhat... annoyed by the first interpretation...
On the other hand it's implied fairly strongly that the narrator has feelings for the other football thug, and that both of them grew up eventually, but in different directions.
La oreja de Van Gogh: The song "Jueves" is about a man and a woman who confess their love for each other on a train... just seconds before dying in the terrorist attacks of March 11th.
"Futari wa" ("The Two of Us") by Miyuki Nakajima. The song tells a modern variation on Love Above One's Station: the love between a prostitute and a client who cannot have an actual relationship with her without being rejected by his friends.
"Havana Moon" by Chuck Berry sings a tale about a man waiting at a dock for the eponymous boat, carrying a tourist he fell in love with. He dreams of them moving to the Big Applesauce, but the boat carrying her never arrives. Swigging rum, he decides her promise to come back for him was a lie, and sleeps off the alcohol... and the boat comes. The woman looks everywhere for him until dawn, where she decides to leave port, heartbroken. He wakes up as the boat sounds its last call, and reaches - just in time to see Havana Moon sail into the horizon.
"Running Bear", famously sung by Johnny Preston, is essentially a Romeo and Juliet story between two Indians from warring tribes, culminating in the pair diving into a river they had no hope of swimming through so they could meet in the middle to drown.
Parodied (but nevertheless sad) in "Misalliance" by Flanders and Swann, about a honeysuckle and a bindweed who fall in love. Their families object because the honeysuckles twine in one direction and the bindweeds twine in the other.
"The Leader of the Pack" by the Shangri-Las, im which the guy dies in a motorcycle accident immediately after their breakup.
DAT's animated clip "Showtime" tells the story of a devil that falls in love with a young woman, but he slowly starts becoming human - and feeling a lot of pain - because of their relationship, so he erases her memories of him with a tear in his eye before leaving her. Strange enough, the song talks about "hope for our future".
The animated character and his real-world girlfriend in the video for A-ha's "Take on Me". The story is concluded at the beginning of the "The Sun Always Shines on TV" video: the man suddenly turns back into a cartoon after having died and being revived into a human, then he has to leave the girl behind.
Also the narrator and his ex-girlfriend in Manhattan Skyline. They refuse to get in a Long-Distance Relationship, the girl leaves on a boat, the guy angsts about how he won't be able to fall in love again ever... and then decides to leave to New York.
The song "Que no destrocen tu vida" ("Don't let them tear your life apart") by Los Prisioneros (also covered by La Ley) is about a person whose close friend and said friend's girlfriend are in this situation, and is telling them to not give up on their relationship.
One of the main themes of the song Fatal by The Amazing BrandO. The trope is even mentioned by name.
The German folk song Es fiel ein Reif in der Frühlingsnacht ("A rime (or hoar-frost) fell in the night of spring") frames it succintly in four verses of three lines each: A boy loves a girl, they run away from home and Sie liefen weit ins fremde Land, / Sie hatten weder Glück noch Stern, / Sie sind verdorben, gestorben. ("They ran far into the strange land, / They had neither fortune nor star, / They perished, they died.")
The Finnish Päivänsäde ja Menninäinen ("The Ray of Light and the Goblin") features a feminine mote of light that lingers behind for a little while as the sun sets below the horizon, long enough to have a chance meeting with a troll that rises from his burrow to wander the night. Though even looking at her burns his eyes, he is instantly dazzled by her beauty, to the point of immediately proposing to her and offering to live with her down in his cave. She kindly declines, pointing out that the darkness would kill her - and on that note, that she has to quickly leave and follow the sun and her sisters before succumbing to the night. She is left pondering this encounter as the song ends, suggesting that the attraction was mutual to an extent.
The Italian folk song 'O surdato 'nnammurato (The Soldier in Love), is a very good example of this trope and is probably the most famous example of "canzone napoletana" - to the point Naples's local football club, SSC Napoli, has adopted it as its unofficial anthem. The song talks about the grief of a soldier in the frontlines of World War I who pines for his lover at home. Despite its cheery tone, its lyrical content is heart-wrenching to the utmost extent.
"Fresh Static Snow" by Porter Robinson is a somewhat more modern take on this, being about two people who could be perfect lovers who are implied to be able to connect with technology, but are ultimately doomed because they still may never meet each other.
The frozen white noise static snow, that is your memory... Although I know we'll never meet you're ever part of me... You'd fit perfectly to me, we'd end our loneliness, melt this curse away Though I'll never know your name I'll cry for you the same.
Romeo & Cinderella by Hatsune Miku is about a schoolgirl who meets her boyfriend in secret because her parents don't approve of their relationship.
Prisoner by Len Kagamine features a young prisoner who falls in love with a girl who communicates with him by paper planes. The girl eventually goes away on a long trip, during which time the boy is put to death by gas chamber after fighting with the guards; his last words wondering what her name was, as she never told him.
The sequel, Paper Planes by Rin Kagamine then reveals she is an ill girl, who snuck away from the hospital each day to see him, despite the risk to her health. Her father was a guard at the prison who forbade her to see him and then instigated the fight with him as an excuse to put him to death. The girl succumbs to her illness months later.
Possibly the second most known Teenage Death Song (after "Leader of the Pack") is "Run Joey Run" by David Geddes. Boy (implied) knocks girl up, father gets mad and fetches gun, but not for Shotgun Wedding all could have lived with, but to kill boy. Girl takes bullet for boy and dies, the end.
The song "Catch the Rainbow" from Rainbow's debut album tells the story of a romance that's like catching a rainbow: a beautiful thought, but nothing but a dream which will be dispelled by the light of dawn. According to lyricist Ronnie James Dio, it's the story of a princess and a stablehand who meet at night in the stables to make love, despite knowing it can not last between them.
"English Channel" by singer/songwriter Mark Spiro is written from the perspective of a man pining away for his loved one, who was forced to leave him behind in Continental Europe in order to live and work in London; he notes that he's desperate enough to swim the English Channel just to see her again.
"Life Waster" by Corpse Husband seems to be a pragmatic and realistic take on this. In the song the speaker seems to fall in love with a woman from a very different background or with different life experiences (I went to substances/You went to college), but they nonetheless bond over their different traumas and/or being outsiders. However, this has a Surprisingly Realistic Outcome: as much as they might have bonded together at one point (let the mask off/mixed our tears on the asphalt), and the song contains some common love themes (lyrics talking about stars in your eyes, and If I get to know her then I might save her), their differences and the emotional and physical traumas they have cause them to drift apart. What's worse is that after the drifting apart starts, there are numerous lyrics with references to her lying, hinting at something along the lines of cheating or emotional manipulation, and the situation seems to turn from simply drifting apart due to differences while still caring/being fond of each other (fuck your fucking sickness/lost you in the process/Ima get it for us like I always promised) to becoming outright angry and hostile, especially as it seems like the speaker embraces his own dark side in the last verse.
Humorous version: "Tu mundo y el mío" ("Your world and mine"), by singer/writer/humorist Leo Maslíah, tells the story of two lovers that have serious problems to be together. Initially it seems like the classic story of two people from different social circles, but as the song advances the difficulties become more and more evident: she doesn't speak in Spanish... because she's from Mars; her planet doesn't have water or oxygen for him; she'll be treated as a specimen if she comes to Earth; and he can't go there anyway because he'll never be an astronaut; their bodies are so different that they can't even touch (and she appears to be similar to an Alien xenomorph). The differences pile up and finally the earthling encourages his beloved to forget him.
"Through the Barricade" by Spandau Ballet is about the singer expressing his love for someone "born on different sides of life", and seems to end with them being Together in Death. Word of God is that it was inspired by The Troubles.
is essentially a Romeo and Juliet story between two Indians from warring tribes, culminating in the pair diving into a river they had no hope of swimming through so they could meet in the middle to drown.