I thought it would be interesting to start a thread about the 'blues' of different cultures around the world. I think that every culture has something similar. Music that expresses pain and longing, that grips and doesn't let go.
Rebetiko and fado are probably the best known, but I'll leave them to more knowledgeable posters.
The first kind of music I want to talk about is probably the most unusual, as it has no criminal or underworld connections.
Piyuts are Jewish paraliturgical songs, mostly written by medieval poets, but the tunes are folk tunes. The same tune could be used for many other songs as the words are what is important.
The main thread running through all of them is a sense of yearning, as well as a longing for forgiveness.

El Adon Al Kol Hamaasim.
A song extolling the virtues of the Lord.
www.piyut.org.il/tradition/192.html?section=morePerformances&currPerformance=433&playing=0

El Nora Alila.
Lord of Mighty Deeds is sung in supplication, to beg forgiveness on the Day of Atonement, before the Book of Life is sealed.
Sort of a last chance affair, the song expresses abject humility, that you know what you've done and don't even dare ask for forgiveness on your own merits, but beg that your brothers may be forgiven.
www.piyut.org.il/tradition/110.html?currPerformance=128

Yedid Nefesh.
One of the most important. Excellent information in English in that link, so I won't repeat it.
www.piyut.org.il/textual/english/16.html

Ye'iruni Ra'ayonai.
A man cannot sleep, but ponders the ways of the Lord and prays that the night will stand still and the dawn wait so he can continue to pray and ponder, pouring his heart out before it is time to deal with all the daily affairs.
The whole song is about longing for the Lord, longing to be in his presence.
www.piyut.org.il/tradition/english/2584.html?currPerformance=3343

Ana Ve'ana Hoshia Na.
A Libiyan piyut, it pleads the Lord to save and bless.
Each verse uses a different title (Mighty, Blessed, Compassionate, that sort of thing) for the Lord, which ascends alphabetically.
www.piyut.org.il/tradition/english/2475.html?currPerformance=3216

Im Ninalu.
A yemenite songwhich goes: even if the gates of the generous are closed, the gates of heaven are still open.
www.piyut.org.il/tradition/english/117.html?currPerformance=430

Mezulzelet.
A Morrocan song.
www.piyut.org.il/tradition/english/662.html?currPerformance=860

Finally, here is an example of a modern day piyut, that is, the melody is contemporary, the words I've mentioned above.
El Nora Alila - Meir Banai.
www.youtube.com/watch?v=1P0tnSgv-EE

This site is unbelievable. Hundreds of authentic recordings on top of all the texts.
www.piyut.org.il/english/

Anyway, would love it if people would contribute about other genres.