00:00 Guitar intro (strumming pattern).
00:07 First verse. Notice the how the audience joins in right away. They obviously are already familiar with the song
00:19 Notice the pick-up into the next verse is slightly out of time.
00:27 Notice how the guitar nearly stops when the words of the song become important.
00:48 This is a classic folk moment. There are more syllables than there are notes. He fits them all in regardless.
00:53 The singer now moves away from the melody temporarily and the audience carries the melody.
01:05 The interlude has an extra measure (may be waiting on the audience).
01:08 Next verse.
01:21 Extra measures while the audience claps.
01:42  Notice how he makes a short attempt at singing a countermelody to the audience but it is short lived.  He will try successfully again later.
01:50 Again the interlude is extended. The verbiage into the next verse barely fits the time allowed.
01:58 Again a lot of extra syllables beyond what the melody can accommodate.
02:04 Singing a little more forcefully and improvises melodically. He is able this time to sing above the audience.
02:30 Notice how clearly he makes the words.
02:45 More vocal improvisations (short).
03:03 End.