Marion & all,
   This is not a question of etiquette as much as one of format. Perhaps a bit of history on these mentioned venues will clarify this.
   The Highland Guitar Society gathers in Judique, Cape Breton every second Sunday, from September through June. $3.00 is charged at the door and it is used to pay rental for the hall with anything surplus going to charity. Everyone pays this, performers, MC, canteen workers ,sound man and audience,   Everyone who pays this fee becomes a voting member of the organization.
This was started nearly a decade ago by a small group of guitar players and it was a jam session where guitarists sat in a circle playing together. Singing was included as well as picking and all joined in. It was a way for less gifted players, such as myself to try and follow those who had much greater ability.
As people heard about these sessions , they asked if they could attend and watch, and they were welcomed into the group. However, this changed the format somewhat, to more of a concert setting with an ever growing audience. The circle grew too large so a theater style seating
replaced it. The front three rows were reserved for those with guitars
who played along with those who were on the stage. Every player was encouraged to take his or her turn on stage so this then evolved into a bit of an open mike show , but with this twist: What would normally be an audience were playing along, as the original mission was not lost. Those performing up front have the benefit of the sound system with jacked or miked insturments as well as voice mikes and monitor speakers, so they should be in control of their performance. A couple of our best players were asked so often to play backup that it was less hectic if they just stayed on stage.
Today we still follow this format , except that backup players no longer stay on the stage unless they are requested , but they do play in the front rows. The type of material played is whatever the person up front desires. Mainly classic country, folk,celtic and bluegrass but it could be just about anything. It is not just guitars either. You will find fiddles , harmonicas, squeezeboxes etc. but the emphasis is on the guitar.
This format may seem strange to a newcomer but it seems to work for the most part and the audience keeps comming back. We all leave our egos at the door and just have some fun.
The second venue is at the Blue's Mills firehall, located about 5 miles west of Whycocomagh. It is a fundraiser for the Blue's Mills Fire Dept. Many of the same performers gather there every second Friday on the opposite week to Judique. This is a much smaller hall and is more of a concert than a jam session. Due to it being a very crowded venue anyone performing a number or two may lose their audience seat as it often becomes standing room only. People not on stage don't usually play along but when Marion wrote this a few years back it followed closer to the Judique format. Also the two guitarists mentioned were for a time asked to stay up as a bit of a house band.
This is more explaination than justification . My personal opinion is that in a concert format I would prefer to request backup, if desired. I have no problem with these two players as they are far better than myself and I am used to them. I have been in situations though where the sound of my own guitar was being drowned out and due to my limited vocal range I need it to keep me on key.
When the MC said that the guitar player was the best on Cape Breton he was expressing his opinion. To my mind that title belongs to JP Cormier who is also the best in Canada on celtic guitar. Yes Murray, I know that Tony McManus moved to Toronto but that dosen't change my ranking! :-}
I suspect that it was Ciffie Carter who is one of the most talented people that I have ever met. He is both a great fiddler and guitarist. He can play anything with strings very well , and is largely unknown because he plays for pleasure rather than for a living. I have seen Buddy MacMaster come into the audience to ask Ciffie to come on stage and acompany him. Ciffie can hold his own with any of the best!
As for my own ability it is limited and is only a hobby. My mother was a wonderful singer , and as a cruel twist of fate I inherited her passion but none of her talent. I do a bit of songwriting and I will tack on a song that I wrote about the Blues Mills Ceilidh. The tune is obviosly borrowed from the IRA. (Harold Campbell is the Blue's Mills MC )
             Sandy

THE BLUE'S MILLS SONG

                                                                                       
    NOW TELL ME HAROLD CAMPBELL ,TELL ME WHY YOU HURRY SO
                                                                           
    YOUR SPIRIT SO UPLIFTED AND YOUR EYES ARE ALL AGLOW
                                                                                          
    I BEAR NEWS ABOUT A CEILIDH , GET YOU READY QUICK AND SOON
                                                                                          
    FOR THE WHOLE GANG GETS TOGETHER AT THE RISING OF THE MOON
                                                                                 
    AT THE RISING OF THE MOON , AT THE RISING OF THE MOON
                        
    THE WHOLE GANG GETS TOGETHER AT THE RISING OF THE MOON


    OH, THEN TELL ME HAROLD CAMPBELL WHERE THIS GATHERING IS TO BE
    AT THE FIRE HALL IN BLUE'S MILLS , RIGHT WELL KNOWN TO YOU AND ME
    WITH NO FURTHER WORD NEED SPOKEN WE WILL ALL BE HEADING SOON
    TO THE FIRE HALL IN BLUES MILLS AT THE RISING OF THE MOON
    AT THE RISING OF THE MOON , AT THE RISING OF THE MOON
    TO THE FIRE HALL IN BLUES MILLS AT THE RISING OF THE MOON

    NOW THERE'S RITA ON HARMONICA , SHE PLAYS THE OLD TIME TUNES
    WHILE BARBARA PLAYS THE SQUEEZE BOX , AND SHE'LL SING A SONG OR TWO
    THERE'S CIFFIE ON THE GUITAR , AND HE'LL PLAY THE FIDDLE TOO
    IT'S THE WEST BAY ENTERTAINERS AT THE RISING OF THE MOON
    AT THE RISING OF THE MOON , AT THE RISING OF THE MOON
    IT'S THE WEST BAY ENTERTAINERS AT THE RISING OF THE MOON

    THERE'S CARL AND EDDIE UP ON STAGE , AND JOHNNY SINGS HIS TUNES
    WHEN VINCE OR RONNIE PICK GUITAR THE CROWD IS IN A SWOON
    AND WHEN ROLLIE STEPS UP TO THE FRONT , WE DON'T KNOW WHAT HE'LL DO
    BUT HE'S SURE TO MAKE YOU HAPPY AT THE RISING OF THE MOON
    AT THE RISING OF THE MOON , AT THE RISING OF THE MOON
    HE'S SURE TO MAKE YOU HAPPY AT THE RISING OF THE MOON

    THERE ARE SOME I HAVE NOT MENTIONED ; I HAVE NAMED BUT JUST A FEW
    OF THE MANY FRIENDS WHO GATHER AT THE RISING OF THE MOON
    SO ON EVERY SECOND FRIDAY , IF YOU WANT SOMETHING TO DO
    JUST HEAD ON DOWN TO BLUE'S MILLS AT THE RISING OF THE MOON
    AT THE RISING OF THE MOON , AT THE RISING OF THE MOON
    JUST HEAD ON DOWN TO BLUE'S MILLS AT THE RISING OF THE MOON