upbeat

Adjective

• pleasantly (even unrealistically) optimistic

Noun

• an unaccented beat (especially the last beat of a measure)

• a contented state of being happy and healthy and prosperous
  • the town was finally on the upbeat after our recent troubles
    

Related words

• Synonyms: 
  cheerful , pollyannaish , offbeat , wellbeing , well-being , welfare , eudaemonia , eudaimonia