Such a treat it was to experience the Mark Morris Dance Group back on Oct. 27, also at the Lensic. This lavish evening, sponsored by Performance Santa Fe, brought in a troupe comprising 17 dancers. That is in itself substantial for a touring company, but Morris’ dancers always perform to music played or sung live by members of the company’s music ensemble, which is directed by pianist Colin Fowler. The Oct. 27 performance exemplified how closely these elements of dance and music were interlocked even while occupying separate planes.