Are all grape vines edible

OK, this does sound like a slightly daft question, but we have recently moved house and their is a quite big grape vine in the garden, that had lots of black grapes on it last year (when we viewed the house)
the only label on it unhelpfully said 'see other label for variety', which was no help at all.
I know you can get ornamental grape vines, and I have always assumed these didnt fruit much, but I honest don't know if all grape vines that produce fruit are edible- does anyone know?
I am hoping that once I beat up the 'wild' bamboo that is rampaging around the flower bed I may find a long lost label, but doubt it, and the previous owners were most definitely not gardeners!! 

Many thanks for your help

Just hope it fruits as well this year then, to 'out going owners' had just left the grapes to wither, and there must have been at least 20 good sized bunches, so fingers crossed!!
The local birds did well  from them, so hopefully this year we will do well!!
Many thanks!