I try, I really do, not to judge people who perpetrate wanton apostrophe abuse in hand-lettered signs. We’re all human, mistakes are made, live and let live, I (usually) say.
With that disclaimer, then, let’s rock and roll.
We could also say “let’s rock ‘n’ roll.”
What we should never say? “Let’s rock n’ roll.” Or “rock ‘n roll.”
I recently saw this type of apostrophe misuse in a company’s name. It’s even codified in the company’s logo, so I couldn’t chalk it up to a typo. My entire body twitched.
The problem? You need two apostrophes here or it makes no sense. The apostrophe indicates that letters are missing — without the set, it’s like saying “rock nd roll” or “rock an roll”.
Think of the apostrophes here as bookends: without two of them, the surrounding words won’t have the proper support.
(For what it’s worth, I did try hard indeed to maintain a neutral stance about the overall competency of the branding team that approved this company’s logo…)