Jack says..

"Try taking account of the audience and attempting to get their attention sometime"

Surely this depends on whether there actually is an audience there for the music or it just happens that there are people in the pub for another reason?

If the pub advertises music and/or the musicians are getting paid, it could be assumed that a section of the members have specifically turned up to listen to and watch the proceedings. So, I don't see an issue in making an effort to engage with them up to a point. After all, if they are kept happy, so will the landlord. It doesn't mean that you need to respond to every single request. If they ask for Duelling banjos, Willie McBride, Wild Rover, Brown eyed Girl and so on, just be tactful.

Even in circumstances where the music isn't officially advertised and musicians are "doing it for themselves", if the punters are showing some interest then they ARE an audience after a fashion. There's no harm in showing them a bit of courtesy and respect but, of course, there's no need to pander to them either.

However, on many occasions, a majority if not all the punters in the pub are not particularly interested in the music. They are there to watch the football on the flat screen TV, have a blether with their mates, possibly have meal, play darts/pool/cards etc or whatever else you can do in a bar these days. A minority may enjoy the music and pass comment but most couldn't care less one way or another.

In many ways, this is better for session musicians as long as the other activities are not too noisy or distracting and they can be left in peace.
As for "attempting to get the attention" of the other pub users, what right have the musicians and singers to expect to be the centre of attraction? It's surely more polite to leave the other customers to their own activities? After all, how would you like it if you were having a nice tune and somebody tried to drag you across the room to watch a penalty shoot out on the TV set or to watch the pub's champion pool player in action? So when you are in a bar, it's often better to "Live and let live".