Hello, we live outside of Pittsburgh , PA near Kennywood amusement park. I know several people who work there and there is a tree in the park that has been there for years. It is reported to smell like honeydew melon. I will attach photo if I can figure out how! Ok uploaded.
Possibly a Linden, they are very fragrant when flowering. Here is a close up of Linden foliage a dead give away is their defining seed leaf
Silver Lime Tilia tomentosa. The white undersides of the leaves are very distinctive. ThorFinn - yours is probably Small-leaved Lime Tilia cordata.
Can you add a photo of the underside, too, please! Lime identification is much easier from looking at the density and positioning of the hairs on the underside of the leaf.
