The importance of opera buffa diminished during the Romantic period. Here, the forms were freer and less extended than in the serious genre and the set numbers were linked by recitativo secco, the exception being Donizetti's Don Pasquale in 1843. With Rossini, a standard distribution of four characters is reached: a prima donna soubrette (soprano or mezzo); a light, amorous tenor; a basso cantante or baritone capable of lyrical, mostly ironical expression; and a basso buffo whose vocal skills, largely confined to clear articulation and the ability to "patter", must also extend to the baritone for the purposes of comic duets.[5]