The external drive is mounted and the iTunes folder has around 220,000
tracks in it. Swinsian sees the drive and assesses the tracks just fine.
I had lunch and came back and my Mac had restarted automatically saying
there was a kernel panic. Everything looked OK and I launched beaTunes.
Shortly thereafter the error occurred. I say OK, it goes away but
shortly returns. This just repeats. No other programs were running and
the audio drive was mounted.
Perhaps I need to upgrade the system to High Sierra.