Wine of Qawwali

Nusrat Fateh Ali Khan, the greatest of all qawwali singers, sings, "The eyes of my sweetheart are so bewitching, that even the best wine of the tavern pales in comparison". These words are typical of qawwali, and they must be understood in a Sufi context: the "sweetheart" is the saint or Prophet who one wishes to be spiritually close to, and drunkenness is mystical fervor, self-annihilation (fana). In this stage, the plane of worldly consciousness is dissolved and the ultimate union with the eternal is achieved. The qawwali session may strike a sympathetic chord in the listener, bringing him to this state.
To consider a wine metaphor, looking to Rumi, who writes:

Muhammad was not the cupbearer, he was a goblet,
Full of wine, and God was the cupbearer of the pious".

Or in "Andak Andak":

Little by little, the group of the lovedrunk arrive
Little by little, the worshipers of wine arrive
They are on their way; Comforting and gentle
Like flowers from the flowerfield they arrive
Little by little, from this world of Being and non-Being
The non-existent leave and the existent arrive...

These are symbolic subjects: romantic love serves as an allegory and facet of divine love, while intoxication refers to the joyous trance. In the famous Persian poem "In the Tavern of Ruin," the oft mentioned "tavern" refers to one’s spiritual master who houses God’s love. And Wine is not wine, it is mystical love of God.
Not only the poetry but a melody and a manner of its execution serves the same purpose - to guide its listeners into a state of ecstatic trance (wajd). It is a certain mystic ritual.The music guides its listeners towards a spiritual union with the saints, with the Prophet, and eventually with God.
But these are external manifestations of a spiritual process; internally, the listener has a specific experience where the inner eye should see and the inner ear should hear. Through this, an initial state of concentration may transform into arousal, and finally, into loss of consciousness in ecstasy.
It follows that one who understands the text, music, and performance but does not feel its true holy meaning, cannot truly understand what qawwali is. My personal acceptance is not intellectually so I cannot argue on it. Anyway, the intellect cannot suffice. Especially for stage of ma'rifat. All our rationality is only illusion in comparison with truth of mystical fervor -  and as Hafiz writes :
"Hafiz, never sit a moment without wine and Beloved"