Texted expression of affection after song with little substance (6)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

ILY (text-message abbreviation for I Love You = expression of affection) after AIR (a song). “With little substance” looks like an adjective phrase corresponding to “airy”, but it could also be an adverb phrase: “He spoke with little substance” or “He spoke airily” = he talked vaguely without providing any real information.