②2m+m indicates the number of people in painting group and calligraphy group.
③2m-6 indicates the number of dancers;
④2m-6m means that there are more people in the dance group than in the calligraphy group;
⑤3m- 12 indicates the number of musical instrument groups.
So the answer is: painting group, painting group and calligraphy group, dance group, dance group is more than calligraphy group and instrumental group.