ID of this plant please

[Lilac]

Thanks guys!

The neighbor that gave this to me said that it was gifted to him also. What he gave me was a piece with roots of the original plant. He has it attached to a tree.

I really like it when it blooms it's a spray of many little flowers. But with move to the new house I had placed it in a very sunny spot (unbeknownst to me)
and the first spike burned. Now it has a puny little second spike but I'm sure it will return to it's former glory