Beck and Call vs Beckon Call

I was well into my thirties before I learned that the correct expression is"beck and call", not "beckon call". In fact, the first time I encountered it, I assumed the writer (a business colleague) had made a sophomoric mistake.

In defense of my error, "beckon call" reminds me of other terms such as:

• borning cry
• siren song, swan song
• death rattle

Clearly the grammatically correct usage would be the gerund form, beckonING, as is the case with borning cry. But beckon is already a two-syllable word, and also a less-common word, which I would argue lends itself to a tendency to shorten, for metrical felicity.

My next example is "Siren song". This is not a perfect parallel example, since it does not involve a gerund, but illuminating in that it is an example of shortening for convenience (7.0M Google results for Siren, 1.4M for Siren's). Swan song is even more dramatic--"Swan's" yields very few matches.

My final example is "death rattle", which I see as being substantially parallel. "Dying rattle" barely registers in search numbers--though amusingly, the second hit is a brief poem that addresses the very point that death rattle is the more appealing phrase.

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So I think that is all a good argument that it is almost a sign of good linguistic judgment to assume "beckon call", if one has never seen the term in print. 

But the most compelling, in my mind, is the Occam's Razor take: "beck-and-call" sounds like a textbook example of the simplified, monosyllabic phonetic rendering that is the hallmark of a typical mondegreen(!)

Egg corn vs Mondegreen

I've long been a connoisseur of mondegreens. Only more recently have I become aware of a devilishly similar term, eggcorn. I just spent 15 minutes researching the compare-and-contrast, and I am not sure this is settled law. My quick take: Mondegreens completely alter the meaning of the phrase, while eggcorns keep it at least adjacent (chomping at the bit vs champing at the bit).

Some sources claim that mondegreens are distinguished by a nonsensical meaning, but I think that is a side-effect, not the main effect. I.e., very often the completely different meaning will be off-the-wall, but not always. In fact, the founding mondegreen changes the meaning substantially, but in an entirely sensible way.