SPOILERS FOR YOUR LIE IN APRIL! YOU HAVE BEEN WARNED!
One of the most beautiful anime soundtracks I know is the soundtrack from Your Lie in April. The music is upbeat and happy, but if you're paying close enough attention, you'll realise that the music is extremely sombre and... saddening.
For example, here's Friend A.
Now, the reason I like Friend A is because it doesn't really bother hiding the fact that it's supposed to be sad. It's obviously supposed to be a depressing song, for a moment of... well, sadness.
Now, here's Again.
Again is one of my favourites, because it plays when Kaori tells Kousei to literally play 'again'. She wants to restart the song. She wants the song to go well the second time. She knows that Kousei can do it.
Next, Kousei's Final Song with Kaori.
This is quite literally the final song Kousei plays with Kaori before her... well, her death. Kousei plays with all his heart, hoping that the song will 'get to her'. He hopes that she heard it... because he's playing for her. Kousei loves Kaori.
Finally, my favourite song of all time...
The first opening for Your Lie in April, Hikaru Nara!
Now, without a doubt, Hikaru Nara is the most misleading song in the entire soundtrack. It sets you up for an upbeat, happy anime. Let's look at the English translation of the lyrics.
I fell in love with you that day, as you gazed up at the crimson sky.
Not even an instantaneous frame of this dramatic film will fade,
This just seems like the stereotypical anime lyric thing, right? Boy falls in love with girl, boy thinks that girl will never go away or... something like that.
Along with that, the song in general... is just happy, upbeat, etc.
Who knew an anime like this could be so depressing and have someone make so many memories?