Andreas from Pussy Goes Grrr here, with an especially sobering song selection.
Midway through Akira Kurosawa's life-affirming masterpiece Ikiru (1952), the terminally ill protagonist Watanabe (Takashi Shimura) gives those around him a painful reminder of life's transience. An aging bureaucrat, Watanabe has been trying to indulge in a little of the good life as he dies of stomach cancer. But nothing, not even a fancy new hat, has been able to lift his depression.
At his nadir, Watanabe sits in a bar surrounded by young revelers, with an attractive woman at his side. The piano man calls out for requests, and in a low rasp, Watanabe suggests "Gondola no Uta." The piano man obliges him and, although the bar's denizens initially try to dance, they soon fall still and silent as Watanabe's anguished singing takes over the soundtrack.
Read more about Takashi Shimura's incredible performance (including Ikiru spoilers) after the jump.
It's the most heartbreaking, tearjerking moment in a film full of them, as an elderly man who's wasted his life warns the youth of postwar Japan that their good looks and happiness will soon fade. That soon, they'll become like him. Written in 1915, "Gondola no Uta" appears to be a dimly remembered artifact of Watanabe's own youth. Its chorus, "Life is brief / Fall in love, maidens" is a bittersweet distillation of romantic "seize the day" sentiments.
This is nothing new, but the song is gentle and melancholy—and as sung by Shimura in a quiet, brittle voice, it's just as much memento mori as it is carpe diem. It becomes about the chances that Watanabe never took, his failure to properly raise his son, and the personal inertia that left him working at a soul-sucking desk job for the majority of his life.
Kurosawa pans across the room, surveying the song's effect on all the now-muted partygoers. Then he settles on Shimura's face, holding him in the center of a close-up for the rest of the song. His lips barely move as he forces out the lyrics, and tears drip from his eyes. It's a very unsubtle onslaught of raw 
emotion, but Shimura makes it work; he looks lost in the abyss of his own regret as he stares straight into the camera.
For me, the "Gondola no Uta" scene is on par with the ends of Imitation of Life or Toy Story 3 with its Pavlovian "here come the waterworks" power. As Ikiru wraps up an hour and a half later, Kurosawa capitalizes even further on this scene by having Shimura reprise the performance. In his dying hours, as he sits in a swing at the park he helped build, Watanabe softly sings it to himself. This time, though, he has absolved himself of all regrets.