While "rate this out of 5" is probably a good start, a review rating can be much more interesting than just that. We could rate things by different scales!

I've mostly seen this done with videogames, where something might have a 10 in sound quality, but a 7 in graphics, but I've also seen this in classical music, for example, evaluating the quality of the performance and the quality of the recording (how well you can hear it, is it stereo or mono, etc) as two separate scales. For example, it's hard to compare a mono transfer from the 1930s to a current recording with one scale: some people will care more about the interpretation even if the sound is shoddy, while others will want high quality sound and will not want a noisy transfer even if the interpretation is fantastic.

Additionally, we could have a larger scale (rating things out of five makes sense when rating a lot of things quickly, but for more detailed reviews, 1-10 or even 1-100 might make sense). That would probably be useful if we ever get offered to import external reviews from a source that rates out of 10, for example.