The recent graffiti “tagging” of a newly painted mural in Bond Street has caused quite a stir and throws up interesting questions.

An internationally renowned graffiti artist was commissioned to create a piece of work in Brighton, creating what is being seen as a genuinely artistic image of a violinist.

But then someone “tagged” it – another “graffiti artist” scrawled their nickname over the top of the violinist.

This act of graffiti on graffiti adds to the debate of what is art, who is it for and who gets to decide what creations concepts fall under this umbrella?

These are by no means new questions. Artists and others have been mulling over the issue for aeons.

But even when it is accepted that art is open to all of us to create, a kind of hierarchy still exists.

The person responsible for the aforementioned commissioned mural was Frenchman Xavier Prou, aka Blek Le Rat. The celebrated street artist, who rose to prominence in the 1980s and is one of celebrated British artist Banksy’s main influences, was commissioned by Art Republic to create the mural. He created the image of his son playing the violin.

His work is considered art. Blek Le Rat is a household name and the piece was sanctioned by those whose property he has painted it on.

The identity of the perpetrator of the vandalism is unknown. They covered the Frenchman’s stencil art with crudely painted yellow letters.

The reaction has been condemnatory. It is clear, the first piece of graffiti is art, while the second is most definitely not. Whether the latter was intended as art is a different question.

Blek Le Rat is held in high esteem. However, his stencils were not always viewed with such benevolence.

In 1991 he was arrested while stencilling a replica of the Madonna and Child painting.

Looking back to the 1990s it seems unlikely that anyone would have kicked up much of a fuss had someone spray-painted their tag over the top of one of his stencils.

Don’t get me wrong. In this particular instance, the graffiti that has been sprayed on top of Blek Le Rat’s stencil is nothing of note, and certainly does not add to the aesthetic.

I have no difficulty in appreciating well-crafted street art, or graffiti, and firmly believe such pieces can massively enrich the built environment.

But when street art ceases to be at all subversive or controversial, I argue that something is lost.

But it seemed strange to me to hear of Blek Le Rat being critical of the person who defaced his art.

The tradition that he himself comes from has in the recent past, if not so much at the current time, not been recognised by the mainstream as art.

Marking street art out as worthy of special treatment, as something permanent and never to be tampered with, seems to not be in the spirit of the original concept itself.

This leads me on to the hierarchy among graffiti artists, in which Blek Le Rat ranks pretty highly, and as such commands respect from fellow artists.

Following the defacing of his latest work, the artist said that this had broken an unspoken rule among street artists, which is to leave a piece of art alone provided it is well-finished and well-executed.

This is one reason there has been such outrage – the community of street artists being largely respectful of each other’s work.

Another reason for the response is that Xavier Prou is a living legend of sorts in some circles.

It is unfortunate that what was a strong and eye-catching image has been partially obscured with something so unimaginative, and obviously comes as a blow for Art Republic, which commissioned the piece.

However, I would argue that by its very nature street art has a transitory element to it.

Without locking the work behind glass, perspex or some other security system, there is no foolproof way to protect it, and that is obviously not practical.

It is the very fact that this art is accessible outside of the confines of the traditional gallery environment that makes it so appealing.

Anyone who lives in Brighton may feel a sense of shared ownership of the city’s street art. They may have favourite pieces along well-trodden routes.

The downside to that, of course, is that such pieces are vulnerable to the elements or anybody just wanting to make a statement.

The Frenchman made his name painting on to property without permission so can he really be critical when somebody paints on his work?