There have been times when I've poured my heart and soul into playing the piano. I'll give it everything I have. Then I'll pause for a moment and look around the room and it seems as if no one even noticed music was playing. As if I could very well be there for decoration and nothing more.
And just when I've resigned myself to that fact, someone will approach me. Sometimes they have an extravagant story and choke back emotion as they explain, "My Aunts from Germany sang that song all the time when I was little. I haven't heard it 40 years!" Or sometimes, it's a simple smile and understated, "Nice music." Other times, I just catch someone out of the corner of my eye at their table, mouthing the words to the song I'm playing.
Then I silently reprimand myself for once again forgetting.
You may not always know who is listening. But you're always heard.