# What is the best way to write labels for chord inversions?

Please see this image from a textbook which asks me to label the chord inversions seen in the exercise.

You will see that my answer in the second set of chords is different but this is the way that I have always written inversions. Is this incorrect?

If anything I should probably choose the other way of notating chord inversions which is to put the letter and then a slash with the other letter underneath. For example C/E. Isn't this method much more common than putting the letters a b or c next to the Roman numeral?

There are three different systems being discussed here. "Letter-slash-letter," like `C/E`, is simple chord notation, used in lead sheet and other contexts. It's really a notational system, that tells performers what to play, but it doesn't say anything about diatonic harmonic function for analytical purposes. (I sometimes use it as a first step in difficult analysis—"Ok, I don't know what the heck is going on here, but that's a C chord with an E in the bass, let's start there.")

The answers you've penciled in are the system I'm familiar with: Roman numerals plus numbers to indicate inversion by interval.

The book's analysis of the example is another system, using "a" for root position, "b" for first inversion, and "c" for second. (Can someone enlighten me, are there official names for these two systems?)

Note: Your title asks what is the "best" way. This of course sounds subjective, but the objective answer is "whatever's appropriate for your context." If you're writing pop or jazz lead sheet, use letters (though I know a former Muscle Shoals session guitarist who likes to read from a modified Roman Numeral system to make transposition easy). If you're taking a test under a system that wants "a b c" for inversions, use that.

• I have not see the a b c system all that much.. is it really important?
– user35708
Sep 10, 2021 at 13:55
• Good question. I first encountered it, like, last week, but my perception is it's common in the UK? en.wikipedia.org/wiki/Talk%3AInversion_(music) suggests that it's used in exams there. Obviously it's the system your book is using. I wonder whether someone more knowledgeable than me can confirm how widespread it is elsewhere. Sep 10, 2021 at 21:19
• I believe it's a UK convention, I've rarely seen it in North America. I'm always afraid that the "b" for first inversion is going to be read as a flat! (Of course, the "6" for first inversion isn't much better because of the modern major add 6 chord...) Sep 10, 2021 at 22:28