Remember HMV’s listening posts? Back in the day, the British retailer’s display units were one of the key ways music fans could sample new albums before deciding whether to buy them on CD.

Now the idea is getting an appy update for 2012. HMV has launched a free iPhone app called HMV Listening Post, which offers similar preview features.

“Listen to music previews by taking a photo of a CD cover or searching for an artist. The hmv listening post recognises albums from a photo or search and enables you to listen to preview clips from the track listing,” explains its listing.

We’ve been playing with the app this morning: the samples are streams, but the app doesn’t tie into Apple’s iTunes store. Instead, a ‘Buy CD’ button takes you (via the Safari browser) to the HMV.com mobile store.

So, to reiterate: take a photo of a CD cover, in order to buy the CD from a website. Hmm.