A star cluster, or, perhaps, a local group might be used to describe a "closely associated" number of stars which are part of a larger stellar group, like a galactic arm or the like. D. Galaxy
I think you need to better define what you mean by "configuration". If you mean a pattern of stars with which you can play connect-the-dots to form a picture in the sky, that configuration is called a constellation. If by configuration you mean a close grouping of stars, it would be called a cluster if the total number of stars was in the hundreds of thousands to millions, or even a galaxy of the total number of stars was in the hundres of millions to billions.
That is commonly called a gas giant.
The musical Cats is an ensemble piece, but Betty Buckley starred as Grizabella the Glamour Cat, who sang Cats' signature song, Memory.
"Teardrop" by Massive Attack is used in the US. In many places overseas, because of copyright issues, the show has a different theme song, written specifically for the show. You can also hear this alternate theme song during the end credits of the show everywhere.
Chip
A Balinese music ensemble is called a gamelan, which refers to the instruments used.
An ensemble
Band or Wind Ensemble
A Quartet
ensemble
It Is called an Orchestra.
A group of performerstrio
A band, a group or musical ensemble
A choir
a band, an ensemble, or an orchestra
It could either be named in accordance to the specific number of players, such as a quartet, or it could simply be called a chamber ensemble.
In general it is known as 'ensemble' - French for 'together'.