Definitions:
done by one person alone; unaccompanied

for or by one person alone

a piece or passage of vocal or instrumental music for one performer

an unaccompanied flight by a pilot in an aircraft

a card game resembling whist in which the players make bids and the highest bidder plays against the others in an attempt to win a specified number of tricks.

a motorbike without a sidecar

perform a piece or passage of music unaccompanied or as the featured musician

fly an aircraft unaccompanied