"What Am I to Do"

I noticed two small things in "What Am I to Do," both in the line "That we must live each night and day apart."  "Night and day" is a merism.  "Apart" is sung with a melisma (C D C A), and since the syllables of the word are sung in something of a disjointed manner, there's a sense of the word's meaning.

"Groovin'"

In "Groovin'," "long" in the line "One of these mornin's and it won't be long" is sung with a melisma (Eb C), so while it's negated, there's a sense of the word's meaning.

"Without You"

In the line "So sad all the time" in "Without You," both "sad" and "time" are sung with melismas (C D and G F D, respectively), giving a sense of degree (for "so") and entirety (for "all").

"5-4-3-2-1"

I found two literary allusions in "5-4-3-2-1."

The first verse:

Onwards, onwards rode the six hundred

Down the valley on their horses they thundered

Ah, but was is them who really blundered

Uh huh, it was the Manfreds

This refers to Alfred, Lord Tennyson's poem "The Charge of the Light Brigade."  The Manfreds even borrow some specific words:  "Half a league onward, / All in the valley of Death / Rode the six hundred" (lines 2-4) and "Some one has blunder'd" (line 12).  "Thundered" also appears in Tennyson's poem, but it doesn't describe the brigade:  "Cannon in front of them / Volley'd and thunder'd" (lines 20-21).

I'm not very confident in one line (the third) of my transcription of the second verse, but it's something like:

The Trojans waited at the gate for weeks

In a wooden horse into the city they sneaked

Pulled out and then, who was it?  The Greeks?

Uh huh, it was the Manfreds

In Book II of Virgil's Aeneid, Aeneas explains that the Greeks built a wooden horse, hid their soldiers inside, and left it by the city, ostensibly as an offering.  The Trojans brought the horse into the city, and when night fell, the Greeks emerged and opened the gates for their fellow soldiers.  In Book IV of The Odyssey, Menelaus briefly recounts this story too.