[Idiom] to get up with the band

[sitifan]

Daisuke Inoue was born in the suburbs of Osaka in 1940. He took up playing the drums when he was in high school. Soon he was playing the drums in a Hawaiian band in the clubs of nearby Kobe. Middle-aged businessmen liked to get up with the band and sing traditional and military songs.
(Guided Practice for Reading Comprehension, by Chu Xiangning et al.)

What does the phrase in red mean?

 

[kadioguy]

Daisuke Inoue was born in the suburbs of Osaka in 1940. He took up playing the drums when he was in high school. Soon he was playing the drums in a Hawaiian band in the clubs of nearby Kobe. Middle-aged businessmen liked to get up with the band and sing traditional and military songs.
(Guided Practice for Reading Comprehension, by Chu Xiangning et al.)

What does the phrase in red mean?

I hope that the following will help.

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get up with (v.) (US black/campus)
1. to meet someone; to get in touch with.
https://greensdictofslang.com/entry/sb26jla#k74a7fy

get up with
To contact someone,to speak to someone, to get a hold of someone.
https://www.urbandictionary.com/define.php?term=get+up+with

 

[SoothingDave]

No, it doesn't help.

Up on the stage.

 

[Charlie Bernstein]

When the band plays, they like to stand up or go up on stage and sing along