Madrigal Debut is an achievement in Halo: The Master Chief Collection. It is unlocked by finding and activating the first Siege of Madrigal music cue on Assault on the Control Room. The achievement is worth 5 gamerpoints and can be unlocked on any difficulty.
The cue can be found most easily on the pyramid structure at the end of the level. There are three brackets on the large tower above the Control Room entrance. The player will need to land on the second one with a Banshee. After landing, face the cliff, and go to the right side of the bracket. The music cue is found at the end of the bracket, just before it slopes down sharply.