'Déjà Vu'
"Basically, this song is a take on what Quincy Jones did with pre-Thriller Michael Jackson. Beyoncé really wanted it to have a street feel to it. On top of the kick pattern there's an 808 and a really busy live bass, which is great. The horns are also live. The potential problem with a record like this is that the drum and bass patterns are very busy, and there is a lot of frequency information that can cause a loss of dynamics and clarity. This was the real challenge for me. I was very concerned, and voiced this to Rodney and Beyoncé, that when the mastering engineer slapped his limiter on the mix to bring up the volume, all the low end would come up as well and you would lose all the bounce, which is the great thing about this record. So I ended up printing a couple of versions with the 808 pulled back, which is what they went with."
'Irreplaceable'
I felt the song was a bit old-school; if Beyoncé wasn't singing this, you would think it was a pop or a rock song
http://www.soundonsound.com/sos/apr07/articles/insidetrack_0407.htm