Puzzle House #1: Entrance Hall

Question

So, after typing in the solution to the Calculator Bomb, I stepped into my house, and was immediately overwhelmed by the number of traps and puzzle-seeming things littered around the room. Whoever did this, they definitely pulled out all the stops. The door leading to the kitchen was locked, and all the other doors out of the entrance hall were so barred that I didn't even want to try to undo them.

I looked around for another note from the person who did this, and I found:

Hello again. Miss us? We thought the calculator wouldn't stop you. So, we've trapped your entire house with puzzles. If you make it all the way to the back of the closet in the bedroom on the top left, you'll find a button that will undo all of this.

Of course, the door closest to the stairs that led to the bedroom they were speaking of was boarded up. There was another staircase, in the back, but I'd have to get there. Which was much easier said than done, considering the circumstances.

Having done a few Escape the Room challenges, I solved a simple puzzle found underneath my carpet, which opened a box, giving me this paper. It read:

Some thought but one, though some had thought a few.

Even shark teeth break arks unless they're new.

Vexed arias play through Asia, the sweetest song.

Everlasting melody has gone moldy before too long.

Never seeing that the singe is already near,

Fourth, third, differences first, second, is the order here.

(end of paper)

The lock on the kitchen door had a keypad and spots to type in four digits from 0 to 9. There was also a warning on the lock.

WARNING: If the wrong combination is typed in, even once, this lock will explode, which will not be fun for you. The order you type the numbers in matters. Oh, and still don't try to call the police. We are watching...

I couldn't find anything else of use around the room.

Good luck. I hope you have it (again)

(This is my first word-based puzzle. I hope it's good!)

Clarification: The paper is the only thing required to solve the puzzle. The rest is flavor.

Hint #1:

In each line except the last, two words are the same, but not quite... and the last line says 'differences first'...

Hint #2:

Notice something similar about the similar words? Perhaps a location will give a clue...

Answer 1

Partial Answer:

In the first block-quote, you do say the line,

If you make it all the way to the back of the closet in the bedroom on the top left, you'll find a button that will undo all of this.

Since the lock on the kitchen door has a keypad, then,

"Top left" might secretly refer to $1$, because the keypad is most likely arranged as follows: $$\begin{array}{|r|c|} \hline 1 &2 &3\\ \hline 4 &5 &6\\ \hline 7 &8 &9\\ \hline \end{array}$$ So $1$ is in the code.

Then in the paper,

There is an acrostic that spells SEVENF which shows $7$F.

The first line says,

Some thought but one, though some had thought a few.

And perhaps,

"One" might refer to how the secret code has another $1$. And also, if there is another $1$ in the code, then you can say there is a "few" of them.

The second line says,

Even shark teeth break arks unless they're new.

And perhaps,

This might refer to an even number (because it starts with "even"). Then, "shark" $-$ "ark" $=$ "sh" (shown in "break arks"). When someone says "sh", they want you to be "quiet". The word "quiet" starts with "q" that looks like a $9$. Now $9$ is not even, but if you go one less (one less = uno less = "unless") then it is $8$. Now it is a "new" number, and even, too.

So overall, this passage might refer to $8$.

The third line, I can't work out.
The fourth line says,

Everlasting melody has gone moldy before too long.

"Melody" $-$ "moldy" = "e". The letter "e" is in the word "before" and is placed second. Second refers to "two" (as said in "too long" since "too" sounds like "two"). Also, "everlasting" starts with "e" and another word for that is "forever". Both words "before" and "forever" have "fore" in them, which sounds like $4$.

So overall, this passage might refer to $4$.

The fifth line, I can't work out.
The sixth line says,

Fourth, third, differences first, second, is the order here.

And perhaps,

This tells us that we should rearrange the passages to get the actual order of the numbers.

So first line is $1$.
Second line is $8$.
Third line, I don't know.
Fourth line is $4$.

Rearranging as fourth, third, differences first and second, you get $4$x$18$. "x" is the number I don't know.

Now from the first block-quote in my answer, since I believe that refers to $1$, we have the order $14$x$18$. Now we have a few ones, if we each get their difference (i.e. do $1-1$) we get $0$. So our new order is $4$x$08$.

Now, the warning says,

If the wrong combination is typed in, even once, this lock will explode, which will not be fun for you.

And perhaps,

"Even once" sounds like "even ones" so an even number of $1$'s will make the lock explode.

Then it says,

The order you type the numbers in matters

So,

The last line of the paper definitely matters.

And finally, the last line is,

Oh, and still don't try to call the police. We are watching...

And perhaps,

This might refer to the numbers $911$. So, the even number of $1$'s refers to two $1$'s that we can't have (which we got rid of before to make $0$). And also, we can't have the number $9$ (we got rid of that to make $8$). So that means the unknown number "x" in the code $\neq 9$ or $1$ and cannot be even, perhaps? My best bet is that because the acrostic spells SEVEN (which is $7$), excluding the F because that is just for the last "ordering" line, I will just let x $= 7$. This also fits the brief, as $7\neq 9$ or $1$ and is not even.

Also, in the keypad, the third box in the first column is $7$. $$\begin{array}{|r|c|} \hline 1 &2 &3\\ \hline 4 &5 &6\\ \hline 7 &8 &9\\ \hline \end{array}$$

Therefore, I am going to guess the code is,

$$4708$$

But I am not too confident with it, so this answer remains partial for the time being.

---

Edit (New Answer):

The third line says,

Vexed arias play through Asia, the sweetest song.

And perhaps,

This might refer to Sweet Song of Asia by Murray Mclauchlan. Also, the word "arias" is contained in "Asia", apart from the letter "r". Now the title "Sweet Song of Asia" has exactly $18$ characters (including spaces), and the letter "r" is the $18$th letter in the alphabet. So $18$ is perhaps an important number here. Then we have the word "vexed" which sounds like "VX". V $= 5$ and X $= 10$ in Roman numerals, so VX $= 15$, I suppose. Since $18$ is "vexed", we might have to do $18-15=3$.

So overall, this passage might refer to $3$.

Using my previous answer but excluding everything that is not in the paper, the code now might be instead,

$$4318$$

This is my new answer. Is this correct?

Answer 2

Partial Solution

Differences

As hinted, there are one letter differences in two of the words of each line
* thought, though
* shark, arks
* arias, Asia
* melody, moldy
* seeing, singe
which spell three, and since "differences first", I guess the code is 3___

Acrostic

The acrostic spells SEVEN, and since "second, is the order here" (the order of the lines), I guess that is the next digit. 37__

Fourth, third
Not sure about these. Could be that the fourth number comes third, or that the fourth digit is the third number, or both, or something else entirely.