Basic Trope: A character sings to his or her Love Interest to convey their passion.
Alice is in love with Bob, and decides that, the next time he visits her house, she's going to sing a song that she wrote herself to express her feelings.
Bob wants to make amends for a past misdeed, so he shows up at a public park (when he knows Alice will be there) with a microphone and soundstage to sing her favorite song: "Wise men say, only fools rush in..."
Exaggerated: Bob hijacks an entire opera and philharmonic orchestra to convince Alice of his affections.
Downplayed: When Alice is trying to tell Bob how she feels, she briefly resorts to humming a love song, before going back into speech.
Alice and/or Bob are musicians, and given to grandiose gestures of romantic affection.
Alice is a wicked sorceress trying to win the love of Chaste Hero, Knight Robert — but an enchanted song wins his heart, sure enough...
The story is set in a Broadway musical; such acts happen all of the time.
Inverted: Alice meets Bob for the first time by hearing him sing at a club, and she loves the music before she loves the person.
Alice sings to Bob — about her past relationships, and why it's too painful to try a new relationship.
Alice is normally a singer, but decides to convey her love for Bob — in painting.
Bob brings out the microphone and soundstage to Alice's workplace to sing a dramatic, passionate Break-Up Song.
Bob comes down with a sudden cold, and decides not to sing — or else tries, and it sounds awful.
Alice finishes her sad song on the piano, and then closes the piano, walks up to Bob, and kisses him.
Just when Bob, humiliated, is about to walk out of the park in tears, Alice picks up the microphone and sings to him, "... But I can't help falling in love with you."
Parodied: Alice tries a private serenade of Bob in her home, but random strangers insist on barging in to serve as backup dancers, much to Alice's embarrassment.
Zig Zagged: ???
Lampshaded: "How did you like me, singing a song just for you? Am I a romantic superhero, or what?"
Invoked: "I will only date the kind of man who can sing. And sing well. And sing to me. ... In public."
Bob is about to sing a love song for Alice in a restaurant. However, she asks him not to do it, telling him that she appreciates the gesture, but she doesn't want the unwelcome attention.
Alice and Bob start dating. Even though Bob cannot sing, he has always loved to sing to his dates and girlfriends. Alice tells Bob that she doesn't really like music, but hints that she adores flowers and jewellery.
Discussed: "Have you heard about Alice and Bob? He took her to a fancy jazz bar, and then he sang for her, accompanying himself on the piano. My friend was at the bar, and she said it was really cool."
"What is your favourite romantic gesture in fiction?" — "I think I like best when there is a guy, singing for her, or for him, and playing some musical instrument. You know I love music."
"Aw, look at that cute young page, singing for his lady with a lute. I love historical films. Don't you?"
Alice has had immense stage fright all of her life, and Bob has helped her to get over that, so she's going to show how much he's helped her — by singing a song for him, in front of the entire club, tonight! But Bob somehow failed to show, so she breaks down instead.
Bob is a massive attention hound, which is why Alice broke up with him in the first place. His public, ostentatious Elvis crooning (complete with embarrassing outfit) only serves to solidify her dislike.
Alice learns that she should get over her stage fright for her own sake, not for Bob's — and a private serenade at her apartment goes much better.
Bob joins a Barbershop Quartet and sings in perfect harmony with them, proving to Alice that he's learned to put his own ego aside.
Untwisted: Alice's painting of love to Bob comes out so awful she burns the evidence and goes with singing instead.