The first thing you notice at Nate Otto’s house is the hearse in the driveway,a 1967 Oldsmobile 98 with tattered curtains and a rusted body.Inside is a small,100-year-old reed organ built for a church.It holds a 1970s-era device:a row of mechanical fingers controlled by signals recorded on a cassette tape deck.It’s just a hint of what’s in Otto’s yard,house and garage:self-playing,old-style musical robots called player pianos.Some sound and look as good as they did a century ago.Some are awaiting repair.Some are being sacrificed for their parts.