After about 4 months of trial and error, I have found this group of songs to be particularly adept at soothing a distressed infant:

Prophecy Theme – Brian Eno
This Lullaby – Queens Of The Stone Age
U, U, D, D, L, R, L, R, A, B, Select, Start – Deftones
The Holy Filament – Mr. Bungle
All Is Full Of Love – Björk
Down In the Park – Gary Numan
Paradise Circus – Massive Attack
The Nurse Who Loved Me – A Perfect Circle
Beautiful Drug (feat. Jana Andevska) – Thievery Corporation
HeavenScent* – Wendy Carlos
Picture In A Frame – Tom Waits
Ego Tripping at the Gates of Hell – The Flaming Lips
The Chauffeur – Duran Duran

*Not surprisingly I was unable find a YouTube video for this track. However I did manage to unearth a picture of the controller that was built specifically for performing and recording this song.

Wendy Carlos rocks.