The harmonic progression of aFCG (Am–F–C–G) and its transpositions constitute one rotation of what I call Axis progressions, namely progressions that begin with one of these four chords and cycle through the others in order, hence the Axis-a, -F, -C, and -G, respectively. Of these four progressions, the a-form and C-form, and to a lesser extent, the F-form, have become staples of mainstream popular songs from the last decades of the twentieth century and the first decades of the twenty-first. The a-form is especially noteworthy for being both extremely widespread and tonally ambiguous, in that the perception of its tonality may waver between the major and Aeolian modes. Not only does the progression conflate aspects of the two modes, but it may also vary the degree to which those modes are expressed and their proportion within the progression, resulting in a vast array of possible tonal se$ings. This article posits that tonality in these se$ings depends primarily on the melodic content of the progression. A methodology for melodic analysis is then presented and applied to a number of examples of Axis-a (as well as some Axis-F) progressions, to demonstrate how diverse its se$ings can be. Volume 23, Number 3, September 2017 Copyright © 2017 Society for Music Theory [1] Tonality in popular music and the ways in which it is manifested in ambiguous se$ings are topics that have only begun to receive regular scholarly a$ention by such writers as Doll (2017), Spicer (2017), Peres (2016), and Tagg (2014). The progression aFCG (Am–F–C–G) and its transpositions constitute one rotation of a set of closely related progressions that, for reasons outlined further below, I call Axis progressions, namely progressions that begin with one of these four chords and cycle through the others in order, hence the Axis-a, -F, -C, and -G, respectively. Of these four progressions, the a-form and C-form, and to a lesser extent the F-form, have become staples of mainstream popular songs from the last decades of the twentieth century and the first

中文翻译：

---

流行音乐轴心进程中的音调歧义

aFCG (Am-F-C-G) 的和声进行及其换位构成了我所说的轴进行的一次旋转，即以这四个和弦之一开始并依次循环其他和弦的进行，因此轴-a 、-F、-C 和 -G 分别。在这四种进行中，a 型和 C 型，以及在较小程度上的 F 型，已成为 20 世纪最后几十年和 21 年代头几十年主流流行歌曲的主要内容。a 形特别值得注意，因为它既广泛使用又在音调上模棱两可，因为对其音调的感知可能会在大调和风神模式之间摇摆不定。级数不仅将两种模式的各个方面混为一谈，而且还可能改变这些模式的表达程度以及它们在级数中的比例，导致了大量可能的音调se$ings。这篇文章假定这些 se$ings 中的音调主要取决于进行的旋律内容。然后介绍了一种旋律分析方法，并将其应用于 Axis-a（以及一些 Axis-F）进行的许多示例，以展示其 se$ings 的多样性。第 23 卷，第 3 期，2017 年 9 月 版权所有 © 2017 音乐理论协会 [1] 流行音乐中的音调及其在模棱两可的音乐中表现出来的方式，这些话题才刚刚开始受到此类人士的定期学术关注。多尔 (2017)、斯派塞 (2017)、佩雷斯 (2016) 和塔格 (2014)。aFCG（Am-F-C-G）级数及其换位构成了一组密切相关的级数的一个循环，出于下文进一步概述的原因，我将其称为轴级数，即以这四个和弦之一开始并依次循环其他和弦的进行，因此分别是轴-a、-F、-C 和-G。在这四种进行中，a 型和 C 型，以及在较小程度上的 F 型，已成为 20 世纪最后几十年和第一个主流流行歌曲的主要内容。