You might be referring to Red Bud which forma a rather large heart shaped dark green leaf. The color is a pure reddish lilac and the flower buds are tiny but profuse. I particularly like the weeping form that I've seen in home landscapes. I'd take a picture of mine but it was an end of year closeout and has just been the ground over this winter. It shouls look better next spring.
Nancon

Some have successfully trained wisteria into a tree form or it has grown up a tree and looks as if the tree is blooming wisteria blossoms. Lilacs can also look a bit wisteria like.

Could it be the Empress tree? It's got that lilac color but I'm not sure if it's blooming yet this year. It's a little weedy the way it self seeds along roads etc. It's from China originally.

Here is a link that might be useful: Empress Tree (Paulownia)

I think they are the Paulownias because I see a ton of them in the woods blooming right now. Eventually they'll leaf out.

Thanks, Kato B and Jenny in Pa. It is a Paulownia tomentosa (Empress Tree). Anne