He trotted onto platform 12 to have a look and found out that it was Night and Day, a collection of photos of Mancunian music venues taken by Jan Chlebik and commissioned and curated by Phil griffin.
Mr Monkey was a little embarrassed to find out later that the collection had been on display since April and neither he nor his humans had noticed, even though they had spotted the removal of the previous display (a series of photos of railway arches across Manchester).
Mr Monkey examined the photos. He found that they were an interesting mix of venues. Some are large, some are small; some are brightly lit and are clearly musical, some don't look like a note has ever been played in them; and some of them were once famous music venues but are now supermarkets or apartments. All the pictures show the outside of the building, without any tricksy camera angles.
Mr Monkey was fascinated by the pictures, particularly when they revealed architectural features - such as the Art-Deco detailing of the Apollo - he'd not noticed when walking past the real buildings.
Mr Monkey thinks Night and Day is an excellent collection, well worth taking a detour to platform 12 to see.
Night and Day runs until some unspecified time in autumn.