pl

function pl
global ca e1 b1 e2 a4n Fs  e12 e13 e14 ch1 ch2 ch3 ch4

Lca=[];

if get(ch1,'value')
    ne1=str2num(get(e1,'string'));
    Lc=ne1+a4n;
    Lca=[Lca Lc];
end

if get(ch2,'value')
    ne2=str2num(get(e12,'string'));
    Lc=ne2+a4n;
    Lca=[Lca Lc];
end

if get(ch3,'value')
    ne3=str2num(get(e13,'string'));
    Lc=ne3+a4n;
    Lca=[Lca Lc];
end

if get(ch4,'value')
    ne4=str2num(get(e14,'string'));
    Lc=ne4+a4n;
    Lca=[Lca Lc];
end



if length(Lca)>0
    
    % define lengths:
    lsa=[];
    for Lcac=1:length(Lca)
        Lc=Lca(Lcac);
        lsa=[lsa length(ca{Lc})];
    end
    lsam=max(lsa);
    
    ss=zeros(lsam,1);
    
    for Lcac=1:length(Lca)
        Lc=Lca(Lcac);
        cae=zeros(lsam-lsa(Lcac),1);
        ss=ss+[ca{Lc}; cae];
    end
    soundsc(ss,Fs);
    

    

    sm='';
    for Lcac=1:length(Lca)
        sm=[sm ' ' number2note(Lca(Lcac)-a4n)];
    end
    set(e2,'string',sm);
    
end