The "crazy part" without captions or sub-titles is called an "Alaap", it has no words so there is no translation. It's a technique used in Eastern classical music to create ambiance or emotion

TMI : The male singer is "RAHAT FATEH ALI KHAN" and is honoured with Doctor of music degree at Oxford university .He's  also a maestro in music.
Fun fact : he is the 17th generation singer in his dynasty and His family has been in music bussiness for over 600 years .
And The female singer is "ABIDA PARVEEN" . She is a Queen of SUFI music. I bet  no one can do it better than her ..in simple words She is a living legend! And What makes her special is the robustness of her voice and clarity of her expression. In live shows, she looks so involved and full of energy, and can switch between slow and fast tunes with effortless ease..
I'd like to add , these two really understand the music.

Fun fact, the singers were here to practice this track, but it went so well that the Coke studio kept it as a final track.

It's not sad, it's deeply emotional and touches the soul of the singers and the listeners. The emotion has to be over the top

It is a ghazal, love poetry, written originally by Amir Khusrao for his spiritual master, Saint Nazimuddin Auliya. At first parts of the song, he writes in imagining himself in the  perspective of a Hindu girl who was enchanted by the pious and high character of Nizamuddin. Therefore, she converts to Islam to try to satisfy him, the 'chaap Tilak sub cheen li ra' chaap tilak is the red dot Hindus endore themselve as a religious symbol and purity , the line meaning you snatched my red dot, thereby every trace of myself. Also, later on in the song, she mentions her to be blessed if Nizamuddin was the one who would color her hue, ie witness her conversion to Islam. He also mentions himself by name, as it is common for poets in Urdu, expressing his devotion to his guru/peer. The song is sung in Old Urdu which was still forming as a new language and still is quite different from other coke studio songs which are sung in modern Urdu/Punjabi. Also, poems are interpretive so they can also be taken as devotion to God, rather than to lover.

In most Punjabi/Urdu poetry the subject is kept anonymous so it can be applied to anything really. You get to decide who the “beloved” is be it an actual lover or god. Don’t read into who they’re talking about, focus on the feeling.

Fun fact ; they were just rehearsing in this video but since they nailed it in their rehearsal so coke studio aired this and actual performance never happened .

This lady has direct connection with the GOD.

It's not a matter of fact whether you like this type of song or not, just imagine the flow of the song and the talent these guys are singing, no one can do that, they are showing their inner emotions to soulful emotions of human nature and humans have different devotions in which they express themselves, just watch how the talent of human nature is in nature and how their devotion is shown in this song, whether you like it or not but as a musician and vocalist know what this song is. Only real Vocalists of the world can know this talent, this is not of your criteria or anyone of us, they are the masters of spiritual songs in the sub-continent.

i would love to see more rappers reacts to this😂😂😂😂😂 its a concept completely alien to them

They 2 are masters, Rahat fateh ali is taught by his uncle ustaad nusrat fateh ali khan and he was grand Master of classical singing
This was live rehearsal , the director like it so much that they decided to keep it that as  original song ...when there no subtitle for Rahat  he was doing  alag ( singing name of note... Like sa  re ga ma pa dha ni, they are same as  western Do, Re Mi Fa  Sol LA ti)
Yes lyrics is sad, actually this poetry is written by Amir khosrow... A Sufi singer, poet, musician and scholar

This poetry was written in 11th century by Ameer Khusroo and sung by hundreds of singers in the past centuries. You can consider it as folk song of the sub-continent (pre-partitioned or United India).

It's sufism, Sufi Kalam
If u jump into it you'll surly love it
Deep meaning 🔥

If you think this is sad, I would suggest listen to Coke Studio "Rang" by Rahat Fateh Ali Khan (same male singer) and Amjad Sabri (late), interestingly the lyrics were written by the same guy, Ameer Khusro who wrote this one about 900 years ago. It has a contrasting feel to this one, a totally jubilant mood.
By the way, just to fill you in about this particular song, "Chaap, and Tilak" referred to as the symbols or things that Hindus wear, so the poet/disciple (Ameer Khusro) acknowledging his spiritual leader (Nizamuddin Auliya) who has been inspirational in reverting lots of non-Muslims to the fold of Islam.

Both are living legends of Pakistan

welcome to music spell of Pakistan 🇵🇰

This song about spiritual love.
It’s my favourite singer's beautiful song.

It was just rehearsal but rehearsal was so.perfect they didn't recorded final.version

Our music taste is so high man and they are our living legends
Appreciate your reaction

At 7:16 he is saying that " if I you loose you're mine and I loose I will be yours" actually expressing that He will never let His lover go and if His lover wants a battle/Quarrel/game for love then he will fight/play on the condition that " if I you loose you're mine and I loose I will be yours"