no sound output on ubuntu server, virtual box

Not sure where to post this issue so I'll start here:
Windoz OS host running Virtual Box and running ubuntu server 16.04 as guest OS. Server install options were minimal: LAMP, SMB.
Wired and wireless network connections working fine.

Wanted to play music so installed moc....Selected music, no sound through laptop speakers.
VBox shows audio output is connected.

Installed and tried speaker-test (alsa utils). Selected default speaker, no joy.
Speakers work fine under windoz.(V10)

I am stuck. I know that VB is quarky but at least the sound should work...
Any suggestions/pointers on how to fix this is appreciated.
thanks
J