This is an off the cuff answer:
for dir in $(ls ); do echo " $dir - this is the directory"; for csv in $(ls $dir/*csv); do cat $csv|sed -e "s/\(.*\)/$dir, \1/g"; done; done
You could then add options to specify file names, e.g.
for myfile in EA_sing EA_ska EA-tat; do for csv in $(ls $dir/$myfile*)...
and then pipe them to a file of your choice, e.g.
do cat $csv|sed -e "s/\(.*\)/$dir, \1/g" >> $(echo "$myfile_complete.csv")