It's a pretty bloom and a very healthy looking bush! I wish I could tell you what it is but I'm afraid it doesn't look familiar. But from that leaf photo I'd say it isn't and old garden rose though. It definitely looks like a modern leaf form.

Thank you! I do love this rose and will try to learn to care for it properly. It was a nice thing to inherit with the yard.

I also sent an email to the local rose club, and I got a response from their "old garden rose expert". He believes it is a variety of Hybrid Musk Rose. The size, the flower type, the foliage, continuous blooms, etc. are all characteristic in his opinion, but he couldn't be specific on the variety.

When your rose opens more flowers, be sure to post photos here and we'll see if we can narrow down your ID.

Thank you, I will do that. I'm thinking by the weekend it will be loaded with blooms. They're all just starting to pop now. The one above was a singleton, very early from the rest.

Looks like Sky's the Limit. It does very well here.

Here is a link that might be useful: Sky's the Limit

Thank you for the suggestion. Perhaps the photo is misleading, but this flower is most definitely white.

Here's some more photos: