Like all open-ended questions the answer is yes & no!

If you mean the endless, looping of your favourite fragment of music in the background, with no way of stopping it, then the answer is a definite NO! This is a bad idea as sound slows pages down and often it is just annoying and distracting

Not just a gimmick 

However, there are many situations when sound, not necessarily music, would be not just a gimmick but a positive benefit to a visitor.

Positive benefit to a visitor is the crux of the answer!

If adding sound to your web site helps to communicate your message - you could consider adding sound.

If (for example,) you had a tip or two about your product, its application, or description of its use then it could make sense to provide a few relevant sound clips. 

But remember give people the choice to download or a means of listening to it on your page.