And the list continues:
Golden Chain Tree, Laburnum x watereri 'Vossii'
Goldenrain Tree, Koelreuteria paniculata
Chinese fringe tree, Chionanthus retusus
Red buckeye, Aesculus pavia
Devil's Walking Stick, Aralia elata 'Variegata'
Smoke Tree, Cotinus coggygria
American Smoke Tree, Cotinus obovatus
Green Hawthorn, Crataegus viridis 'Winter king' (My personal favorite of the hawthorns, but I really like many of them.
Carolina silverbell, Halesia carolina
Kosar hybrid magnolia, Magnolia x lilifora
Ballerina loebner magnolia, Magnolia x loebneri 'Ballerina'
Saucer magnolia, Magnolia x soulangeana
Pink star magnolia, Magnolia stellata 'Rosea'
Species of flowering crabs, cherries, almonds simply abound.
Chinese pistache, Pistacia chinensis
Amur chokecherry, Prunus maackii
And this doesn't even address all of the "large shrubs/small tree" category which, since they tend to be multi-stemmed might suit your purposes better.
Can you give a more visual on your planting site? You stated it is an open corner in the back yard with full sun, which is helpful. But is it northeast or northwest, southeast or west etc. Is this a grass area or planting bed already. Are you planning on more flowers, shrubs, plants in the future? Do you have your outdoor eating area here? If a flowering tree/shrub, do you have color choices? Any allergies? Many beautiful blooming trees can become a nightmare if you can't breath during the entire season they are displaying.
Take a trip to your local nursery or arboretum and see what they have you like, then possibly devise a short list and ask for comments on those. Many trees which sound good on the tag, have inherent problems that we as professionals have become familiar with. Of course, the arborists in your area will hopefully respond as they will be the most informed with the choices you may make. For instance in my list above, I chose plants suitable for Zone 4b to about 6b, but that may or may not be best for where you are situated.
It is always fun to try to help someone select a plant so don't be shy about vocalizing likes and dislikes. Trees are an investment both in time and money so it is really frustrating to discover 5 years down the road, that the selection wasn't what you were expecting.
Sylvia