Kal'Hyah
Kal'Hyah was the path of clarity, sometimes referred to as a "Klingon bachelor party". It was a "mental and spiritual journey" that the groom and his closest male friends took part in before the wedding. Over the course of four days described as being "filled with song and fellowship", one was required to endure six trials: deprivation, blood, pain, sacrifice, anguish, and death. One had to do this while fasting. 

 

In 2374, prior to his marriage to Jadzia Dax, Worf underwent the kal'Hyah in a Deep Space 9 holosuite. His companions were General Martok, Benjamin Sisko, Miles O'Brien, Julian Bashir, and Alexander Rozhenko. All but Martok were somewhat unprepared for the ritual, as they were expecting something more akin to a more traditional Human bachelor party. ()

Noted songs 
While on the path to kal'Hyah, in addition to the trials, it was traditional to sing:

Ka vek ko lee ko
Eh to che mah lo
Tah oo-wah kah esh to pah deh ah reee!
Yah bosh-ah! Yah bosh-ah!
Yah bosh tomah!

External link
 

de:Kal'Hyah
Klingon ceremonies
Klingonese