I avoided giving songs a score from x/10 in all of my roulettes and simply stack ranked them (in various ways). Best song of the round gets the most points, followed by the next etc. You can change this up as well, to not have scores ranging from 1-10, for instance by giving the best song 5 point, the two next ones 4 points both etc. Keeps it a bit more exciting.
I used methods like this in all four roulettes I've ran over the past years, because I can't get myself to give a score based on x/10 /5 /whatever. I feel like too much randomness comes into place there and I would make it too difficult for myself, since my scores would have to reflect on the round I score them in, but also on previous rounds - i.e. a 9 in round 1 would have to be a 'better' song than an 8,8 in round 7 (no offence meant to any and all roulette hosts who do this though!), whereas with stack ranking, you're just comparing the songs to the other songs in the round based on how you feel about them at that time.