The sharp 11 chord extension was used quite a bit in the 1960s. As well as working as an upper structure “colour” note it can function as a flat 5 flex-tone (see the section on blues scales here – Link) A raised fourth degree also gives the Lydian mode it’s characteristic sound. The mode was receiving a lot of attention at this time because of George Russell’s book “Lydian Chromatic Concept of Tonal Organization”. The chords have a nice bite with its semi tone to the 5th and a tritone to the root.