Sing the blues and Singing the blues

Singing the blues and sing the blues are semantically related In some cases you can use "Singing the blues" instead a verb phrase "Sing the blues".

Sing the blues and singing the blues are semantically related in lament topic. Sometimes you can use "Sing the blues" instead a verb phrase "Singing the blues", if it concerns topics such as grieved, regret, mourn, suffer or cause another to suffer.