Source: http://www.davidgentleman.com.David Gentleman. License: All Rights Reserved.

This poster design by fashionable in the 1970s. In case you are looking for a digital font that comes close to this, forget about the ones that are named Helvetica. Apart from the too loose spacing and the differences in the overall proportions, they don't have that restrained exit stroke on 'a'. Better options are Neue Haas Grotesk Display Medium and URW's Nimbus Sans P (Poster) Bold. Latter has the longer ascender on 't'.