What are the most popular keys sung by Tenors and Altos

[brittrich]

I'm a beginning keyboardist\pianist, and I'm curious to know which are the most popular keys sung by Tenors,Altos and then Sopranos.  I'd like to be able to accompany a soloist, by ear. I'm currently learning the 12 Major keys.

Thanks in advance.

In my experience, most tenors I know sung in either F, C# or Ab.  Most altos sung in Eb or Bb.  Most sopranos usually sung in either F# or C.  Sometimes an alto will throw me a A natural or a D.