I am a member of the church of Christ and I want to know is group singing OK during a fellowship? Of course, the fellowship service is dismissed and then the group singing begins. Can you please help me with this?
Your terminology is confusing to me because it is not how things are worded in the Bible, so forgive me if I happen to misunderstand your question.
It sounds like you are gathering together for worship, as God commands, but then after the service formally ends (though almost everyone remains), you have a period of time when one or more groups come before the congregation to entertain them in song.
The difficulty that I have is finding scriptural justification for such a thing to be done. Since it is being done right after worship, that implies it has been connected with the work of the church. Where do we find justification that a church is to provide opportunities for small groups of Christians to sing in what amounts to entertainment for the rest of the members?
If the regular worship service was over and an invitation was offered that any who want to remain for a period of singing together, as per Ephesians 5:19 and Colossians 3:16, I would have no problems with it since it would be time when everyone was singing. But use groups, choirs, or solos I would want to first see the justification.