Usually hand painted on these posters.

Even if I have to agree with Nick Cooke, I guess it would possible to find a decent alternative for this one, may be simply customizing /G (removing horizontal bar and adding a flare serif by slightly curving bottom right part).
Some suggestions Proxima Nova Black (mixing Regular, Condensed or Extra Condensed), Profile, Gibson Bold, Gotham (also mixing styles Regular, Narrow, Extra Narrow...), Polarband, TS Montreal or even a manipulated Futura Extra Bold (but you'd have to entirely redraw /G or to borrow it from one of the previous')