The first arrangement was played by Kingfish and GD thru 9/27/76. The lead was played over the intro and 1st half of the 3rd verse. Then, the vocals came back in on the 2nd half of the 3rd verse ("...way you always 'lectrify me...).
The 2nd arrangement was introduced by GD on 9/30/76. The lead was extended to include a full verse and chorus. Then, the entire 3rd verse was sung. So, this marks the first time the first half of the 3rd verse was sung.
I wonder when the lyrics for the first half of the 3rd verse were written.
I haven't verified if the arrangement changed after the 2nd version. Wouldn't be surprised if it did.