Lilac.

Common lilac (Syringa vulgaris) specifically. It looks to be thriving and will get a lot bigger than it is now, but seems to have plenty of room around it. However since these are pretty much a one note shrub with their fragrant spring flowers being the entire basis for interest in them planting a suitably sized summer flowering clematis to grow up into yours once the lilac is big enough would greatly expand the amount of color being produced by the involved square footage of real estate.

Thanks for the comments. 2 years now and no flowers.

These don't bloom small. Otherwise the flower buds are set at the ends of the stems in summer, to open the following year. So any cutting back that takes place during this summer-to-spring interval will eliminate or reduce subsequent flowering.

Tx