is/are

is

Why, Gus? Two actions should go with a plural verb. Am I right?

Thanks.

I'm not sure how to explain it, but I believe you are performing a singular action (the combination of the two) and that is why "is" is used.

We will wait for a knowledgeable member to come along and explain it with clarity.

Many thanks, Gus.

Does reworking the sentence help

It is not easy to play the piano and sing at the same time.