Aha...

# cp /usr/src/etc/etc.i386/MAKEDEV /dev/MAKEDEV

My MAKEDEV was out of date.  Sound files still play fast, though.

Thanks, Ken.

    >> I am using a very recent -current build.  When I cat a sound
    >> file to /dev/audio, it plays, but I get an error message:
    >> 
    >> lpt0: out of paper
    >> 
    >> This is quite amusing.

    Ken> as root:

    Ken> cd /dev
    Ken> ./MAKEDEV all