Final answer:
The linking verb is 'sets' and the predicate adjective is 'useful'
Step-by-step explanation:
The linking verb in the sentence is 'sets'. The predicate adjective is 'useful'. The sentence can be rephrased as 'A metronome is useful for music practice and it sets a steady tempo that helps the musician's rhythm stay consistent'.
Learn more about Linking verbs and predicate nouns/adjectives