idyll vs tenson

idyll

noun
  • Any poem or short written piece composed in the style of Theocritus' short pastoral poems, the Idylls. 

  • A composition, usually instrumental, of a pastoral or sentimental character, e.g. Siegfried Idyll by Richard Wagner. 

  • An episode or series of events or circumstances of pastoral or rural simplicity, fit for an idyll; a carefree or lighthearted experience. 

tenson

noun
  • A form of lyric poem used by troubadours in Provençal in which two voices present different sides of an argument, in alternate stanzas, lines, or groups of lines with identical structure. 

How often have the words idyll and tenson occurred in a corpus of books? (source: Google Ngram Viewer )