So, it might seem a little weird to have a page dedicated to how I rate music. I mean, how complicated can it be, right? And the truth is this isn’t really that complicated, but it’s complicated enough to warrant an explanation.
I use iTunes as media player and, as such, also use their standard 5-star rating system. These are my personal ideas of what these five rankings mean:
- 5-star: I LOVE this song! Can’t imagine living without it.
- 4-star: I LOVE this song too!….but not quite as much. Can live without it…for a while.
- 3-star: I LIKE this song! Can live without it, but would miss it.
- 2-star: I don’t like this song. I’ll listen to it, but could easily live without it.
- 1-star: I HATE this song! Turn it off….now!
This 5-star method is perfectly adequate for ranking songs. Things get a bit trickier, however, when ranking albums (I’m old, I still call a collection of songs compiled onto a single release an “album”). A popular method is to apply the same 5-star ranking to entire albums, but this is an injustice in my opinion. Instead, I prefer to aggregate the individual song rankings to determine the album ranking.
The simplest means to do this would be to average the rankings of each song. A ten-song album with five 4-star songs and five 3-star songs would have an album ranking of 3.5 stars:
- Five songs * 5-stars = 25 points plus….
- Five songs * 3-stars = 15 points equals….
- 40 total points divided by 10 songs equals an average ranking of 4.
The problem with this is every song is given the same weight. Imagine, though, if 8 of the songs were 5 minutes long, one was 10 mintues long and another 20 minutes long. Imagine also that both the 10-minute and 20-minute songs ranked as 5-star songs. We now have a 75-minute album that breaks down this way:
- Five songs * five minutes * 3-stars
- 3 songs * five minutes * 5 stars
- 1 song * 10 minutes * 5 stars
- 1 song * 20minutes * 5 stars
Adding the minutes of the album we get the following:
- 25 minutes of 3-star songs
- 45 minutes of 5-star songs
A 4.0 rating for this album would imply that half the album is of 3-star quality and half is 5-star quality when clearly that isn’t true. I use a 3-step process to give a weighted average of the album’s individual song rankings:
- Determine the total number of possible “points” by multiplying the album’s total minutes by five (minutes * 5). A perfect 70-minute album with all songs ranking 5-stars would have a score of 350 points.
- Determine the actual number of “points” by multiplying each song’s total minutes by its ranking and then summing them together (sum(song ranking * minutes))
- Divide the total actual points by total possible points
Let’s revisit our previous example and see how this approach changes the result:
- Determine total possible points: 70 minutes * 5 = 350 possible points
- Determine actual number of points:
- song 1: (3 stars * 5 minutes) = 15 points
- song 2: (3 stars * 5 minutes) = 15 points
- song 3: (3 stars * 5 minutes) = 15 points
- song 4: (3 stars * 5 minutes) = 15 points
- song 5: (3 stars * 5 minutes) = 15 points
- song 6: (5 stars * 5 minutes) = 25 points
- song 7: (5 stars * 5 minutes) = 25 points
- song 8: (5 stars * 5 minutes) = 25 points
- song 9: (5 stars * 10 minutes) = 50 points
- song 10: (5 stars * 20 minutes) = 100 points
- This yields a total of 300 points; dividing these actual points by the 350 possible points yields a rating of 85.7 or 86 (300/350=85.7).
So, taking the time of song into consideration the album’s score has changed from 80 to 87. Not a huge difference but for someone like me, who cares about such things, this is important.
Hope that helps.