I'll add my 2c and agree you really need both. I'm a good ear player and a good fake book player but a not so good two handed piano music sight reader. This is why I'm called fairly often to be the rehearsal pianist for two big bands but I've only done a few gigs with them. I've got a good feel for the music and I know a lot of the cool chord voicings but big band music is just that, music. The original charts as received from a publisher do not have any chord symbols written above them but luckily most of the piano charts have those chords written on them by somebody after the fact. Having those chords allows me to get through a tune and that's ok but there's a lot of little specific licks that need to be read and played as written. I was screwed at one rehearsal where there was a written out 16 bar piano solo intro and I had to stop the band for about a minute while I figured out at least the basic thrust of it. When I got home I found the tune on YouTube and that intro is a piece of cake if I could have just heard it for 10 seconds. I can read but not so fast that I can pull out #247 and have the band leader say "you've got the intro, 1-2-3..."
In spite of that I look forward to those rehearsals because one, there's nothing like that sound and two, I really have to stretch to do it.

Bob

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