=comment
	
	# Solo

	$solo = $track_frame->Button;
	my @muted;
	$solo->configure( -command => sub {

		# do nothing if mix track
		
		return if $n == 1; MIX

		# do nothing if setup not connected
		
		return if ! grep{/$project_name/} eval_iam(q(cs-connected));

		# do nothing if someone else is soloing;
		
		return if grep{ is_soloing($_) } grep {$_ != $n} @all_chains; # but some may
		                                                               # not be in
																	   # chain
																	   # setup

		# restore prior mute settings if I had been soloing
		
		if (is_soloing($n) ) {
		
			$solo->configure(-foreground => $old_bg );
			$solo->configure(-activeforeground => $old_bg );

			map{ toggle_mute($_) if $muted[$_] != is_muted($_) } 
				grep{$_ != 1} @all_chains; # MIX
		}

		# otherwise save muted status for each track and mute all
		
		else {
			map{ $mute($_) = is_muted($_) } grep{$_ != 1} @all_chains; # MIX

			map{ toggle_mute($_) } 
			grep {! is_muted($_) } 
			grep {$_ != $n} 
			grep {$_ != 1} 
			@all_chains;

			is_muted($n) and toggle_mute($n);
			
			$solo->configure(-foreground => q(yellow) );
			$solo->configure(-activeforeground => q(yellow) );

			
		}
	});


=cut