Possible Clues:

• Literary comparison
• Came upon a local alternative for what 5 26's 20 was for 12?
• Came across a quartet, in a manner of speaking
• Came across a quartet, by the sound of it, in a manner of speaking
• Homer with apt effect in figure of speech
• Figure of speech that directly indicates a likeness
• Sounds as if one encountered a quartet, in a manner of speaking (8)
• Playing in the pro-am? That's not to be taken literally
• Allegory
• Common figure of speech