Haven't you read this thread in which Pied Piper warns us that the word "Session" is only to be used for activities in which large numbers of instrumentalists all play at the same time (usually Irish tunes at ridiculously fast tempi).

Although it is true that everyone joins in shanty choruses, shanties are usually led by a solo singer - and they are often unaccompanied. Please change the description at once, or I will inform PP and you will be raided be the "Session Police" who will insist on playing large numbers of Melodeons, Fiddles, Whistles, Bodhrans etc to make sure that egotistical singers get no chance to engage in their disgusting solitary vices.