Nice photo, but I'm not so sure about the ID. It can be difficult to separate two very similar species based on a single photo, but there are several reasons I would say Eastern Phoebe:
Timing - Eastern Phoebes have been back for a few weeks, but this would be very early for a Pewee.
Bill - Eastern Wood-pewees have a pale lower mandible. It should be visible in this lighting.
Wings - The wings are probably in partial shadow, but I think the you would still see more distinct wing bars in a Pewee.
Things you can't tell from a photo - This bird was obviously caught making some sound. If it was actually singing (versus a call note), the songs are quite different. Finally, the quickest way to separate them in the field is often the tail-bobbing of the Phoebe. If you watch a Phoebe for 30 seconds, you will probably see him (or her) bob his (or her) tail at least once. Pewees don't.
You can't always tell from a photo, but that's my guess.
BB