To worry about a clean sine wave from the power company is a total waste of time. If you examine the current wave form (not voltage wave form) to a power amplifier, you will see a wave form with between 75% and 150% THD (Total Harmonic Distortion).
Yep. A lot of people (not accusing the OP of this)
are conditioned to expect perfection in everything and are unwilling to accept reasonable variations from the ideal**. They simply don't understand what constitutes acceptable deviation, or why. Pretty much everything (except anally-retentive consumers)
can tolerate some irregularities in the delivered product, whether it is the water going to your dishwasher, the gas pressure to your furnace, or the electricity to your whatever.
I applaud the OP for asking here before complaining. Seeking information -- "is this normal?" or "do I need to look into this further?" are the right questions to ask. Going to the power company with a zero-tolerance attitude saying "MY POWER ISN'T PERFECT!!!1!!" annoys the power company, irritates those whose equipment generates harmonics if the power company makes them do something about it, and ends up raising everyone's prices in a cumulative, roundabout way. And the customer receives no benefit from perfect power, except for a pretty picture on his O-scope.**Except when it comes to the spelling and grammar of their own complaints in public forums and social media.
P.S. -- To paraphrase a famous theologian, "Understandest thou what thou meterest?"