Two years ago, Houston poet Erica Lehrer was diagnosed with multiple system atrophy—ataxia—a rare, incurable, and untreatable neurodegenerative disease that left her unable to speak clearly or for very long.  The disease had not affected her poetic voice, thankfully, just her physical one, so at readings, festivals, and workshops where we were both in attendance, I often volunteered to read her poems for her; our joke was that I had become her “poetry bitch.”  That she maintained a sense of humor about this devastating disease gives a clue to her audacious spirit, and one of her poems that most captures this spirit is the opening poem from Dancing with Ataxia, “Perfect Pitch.” “Perfect Pitch” is a short poem, only fourteen lines, that is filled…