A male may sing an aria.Logical formLearned from21 sentences. Soldiers may sing.Logical formLearned from21 sentences. A genre may sing a name.Logical formLearned from21 sentences. A person may sing lines.Logical formLearned from21 sentences. A female may sing with passion.Logical formLearned from21 sentences. A person may sing birthday to a female.Logical formLearned from21 sentences. A female may sing a (hit song).Logical formLearned from21 sentences. A female may sing about love.Logical formLearned from21 sentences. A female may sing in a chorus.Logical formLearned from21 sentences. Artists may sing.Logical formLearned from21 sentences. A nightingale may sing.Logical formLearned from21 sentences. Crowds may sing.Logical formLearned from21 sentences. Persons may sing in a world-city.Logical formLearned from21 sentences. A male may sing in tune.Logical formLearned from21 sentences. Vocals may be sung by a male.Logical formLearned from20 sentences.