The name and the sporty design. The swoop (the 'swing' motion that also represents the path of the struck ball) sells it too. The Shazam or Pandora icons (avatars) aren't literal musical symbols. Same way with Netflix. No literal symbols (DVD, movie ticket, etc.). The name and user knowledge comes with it. All that being said, do you want a more literal interpretation approach?
The design of the H is nice. I'm not necessarily asking for a literal approach, and I agree with what you're saying. I do feel, though, that we need to be a little more specific about what we are. The swoop motion is nice and a step in the right direction.
Hey Geoff, we've added some feedback up on our page and wanted you to see it... Your original design would work well with what we're on to now... I love to see what you'd come up with! Thanks for the work you've done. Prospect