You can certainly do this without WordArt. First draw a text box (or choose Simple Text box and then delete the text).
After you add the text box, right click and choose Format Shape.
On the Fill and Line Color tabs, set to No fill and No line.
With the text box still selected, on the Format tab choose Text Effects, select Transform, and pick one of the curved shapes.
Now type whatever text you want curved. In the following image I’ve changed the font face, size, and color.
The text won’t look curved until you click outside the box.
When you click on it again, it will look like it did before you clicked outside and you can keep editing the text. Also, you will see a pink circle somewhere on the path, and by dragging it you can adjust the curve. You can drag the green circle to rotate the curve.