Moon, you did magic to me (Tis xenitias) - Dora Giannakopoulou

 Here's a nifty one.   The band takes off and Ms. Giannakopoulou stumbles onto the stage (see below) and  delivers a dazzling performance to a rapturous audience.  

I am guessing (with only circumstantial evidence) that this was a scene from the 1965 movie Storm (Kataigida) which is, according to IMDB, about the relationship between a successful male composer and a singer whose career is going downhill and who is "battling with alcohol dependence".  

The action takes place in what looks like a movie theater.  To top things off, the camera cuts away to an adjoining room where some contentious dialogue takes place, probably about her condition.  Final question -- Is the bouzouki player on the right the same person who did those hot licks at the beginning of the Panos Gavalas and Ria Kourti video?

Yota Agelastopoulou (from the comments, as translated by HRH Google*) puts it much better than I ever could.  She says A unique and unrepeatable story of the people, she shocks us with her words, with her excellent, beautiful, masterfully perfect, enormous interpretation. She has too much emotion (in) her sweet, velvety, beautiful voice; the words come out of her soul with great pity, (and) with bitterness. I'm sorry for the great pain and the languor of alienation. It's too nice a song, too much a touch of the soul, one of the best...   

* While HRH Google did a fine job, I changed the punctuation and added a few small words (in parenthesis) to improve the flow...