In this analysis, we will be examining measures 49-51 of Beethoven's Moonlight Sonata (Opus 27, Number 2, Movement 1).
（在本课，我们将会分析贝多芬的《月光奏鸣曲》（Op. 27, No.2. Mo.1）
Since we are starting in the middle of the piece, I will reveal the key signature: it is in C-sharp minor.
（我们从乐曲的中间开始，这段乐曲是升C小调）
The first half of measure 49 contains G-sharp–B-sharp–D-sharp–F-sharp, a G-sharp dominant seventh chord. Since the B-sharp is the lowest note, the chord is in first inversion.
（第49小节的前半部分包括升G-升B-升D-升F的属七和弦，因为升B是最低音，所以它是第一转位）
The second half of measure 49 contains C-sharp–E–G-sharp, a C-sharp minor triad.
（第49小节的后半部分包括C-升E-升G，是升C的小三和弦）
The first half of measure 50 contains D–F-sharp–A, a D major triad in first inversion. This is the Neapolitan sixth chord in C-sharp minor.
（第50小节的前半部分包括D-升F-A，它是D的大三和弦的第一转位。这就是升C小调的那不勒斯六和弦）
The second half of measure 50 contains G-sharp–B-sharp–F-sharp, a G-sharp dominant seventh chord with a missing fifth.
（第50小节的后半部分包括升G-B升-升F，是省略了五音的升G的属七和弦）
The first part of measure 51 contains C-sharp–E–G-sharp, another C-sharp minor triad.
（第51小节的前半段包括C-升E-G，另一个升C的小三和弦）
Play these measures of Moonlight Sonata.
（演奏一下《月光奏鸣曲》的这几小节） | 