There are catchy tunes, then there's this east London market seller's 'One Pound Fish Song' - a song so catchy you may well end up singing it all day, and possibly even in the shower tomorrow morning.
Known by his YouTube-using fans only as the 'One Pound Fish Man', this Queens Market trader knows how to get people to buy his products: sell 'em cheap, and sell 'em with song.
Sure, some of his maths seems a little squiff at times - if you're doing an offer for six fish for £5, how is that 'One Pound Fish'? - but really, what does that matter when you're so charmed and so eager to buy some fish all of a sudden?
For another angle of aural fishy goodness, check out this alternate take below - and don't forget, if you're near Upton Park or going to a West Ham game any time soon, be sure to stop by for some 'One Pound Fish, One Pound Fish!'
Two doses of the 'One Pound Fish Song' not enough for you? Well, for more public singing and dancing, check out this surprisingly clickable Jumbotron video gallery for you below. Guaranteed to put you in a good mood, we swear it.