"Good" songs and "popular" songs are often not the same. XD Sorry, but modern musique (at least in America) isn't very good.
All the musique I have to suggest isn't in English.
Here's a song that's in Japanese, covered par a Nico Nico Douga singer called Valshe. She's quite populaire for her boyish type voice, which is why she does so many covers of a shouta-type character called Len.
The song is called Soundless Voice, and it's basically about a boy (Len) missing his twin (Rin) who died. (Lyrics here:
link) It's very sad.
Some of the notes are rather low (they're at the very bottom of my range.)
Oh, and if you're interested- there's a sequel to it sung par Rin (and covered par Wotamin) called Proof of Life.
I assure toi it's populaire among the fans of the type of musique I listen to. XD