Generate the names of the keys on a piano

Question

On a standard 88 key piano, each key has a scientific name.

The first three keys are A0, B♭0, and B0. The keys then proceed through C1, D♭1, D1, E♭1, E1, F1, G♭1, G1, A♭1, A1, B♭1, B1, and start over again at C2. This continues up through B7, and the final key is C8.

Any flat can instead be written as a sharp of the preceding note, e.g. D♭4 can also be written C♯4. If necessary, you can write "D♭4" as "Db4".

Your program should build an ordered sequence (array, list, vector, etc.) containing the key names (as strings, symbols, or some similar data structure) in order.

Program length should be measured in characters, to avoid penalizing people who properly generate ♯ or ♭ rather than # or b. However, Unicode recoding is forbidden.

Here is a previous question that might be useful, as it involves taking note names as input.
"Unicode recoding is forbidden." Can you edit the question to explain what that means, please?

PleaseStand · Answer 1 · 2012-07-28 17:31:31Z

Bash shell script (58)

echo {8..0}{B,♭B,A,♭A,G,♭G,F,E,♭E,D,♭D,C}|rev|cut -b40-410

If you do not have rev, you can instead use tac -rs. at a cost of five characters.

Bending the rules, I can subtract thirteen characters (for a score of 45):

echo {8..0}{B,♭B,A,♭A,G,♭G,F,E,♭E,D,♭D,C}|rev

If you really need a bash array, add six characters to the score (for a score of 64):

a=(`echo {8..0}{B,♭B,A,♭A,G,♭G,F,E,♭E,D,♭D,C}|rev|cut -b40-410`)

Howard · Answer 2 · 2012-07-28 15:19:09Z

up vote 5 down vote

GolfScript, 60 57 characters

"A BbB C DbD EbE F GbG Ab"88,{1$2<@2>1$+\{8%},@9+12/+}%\;

The snippet produces the following array (see here):

["A0" "Bb0" "B0" "C1" "Db1" "D1" "Eb1" "E1" "F1" "Gb1" "G1" "Ab1" 
"A1" "Bb1" "B1" "C2" "Db2" "D2" "Eb2" "E2" "F2" "Gb2" "G2" "Ab2" 
"A2" "Bb2" "B2" "C3" "Db3" "D3" "Eb3" "E3" "F3" "Gb3" "G3" "Ab3" 
"A3" "Bb3" "B3" "C4" "Db4" "D4" "Eb4" "E4" "F4" "Gb4" "G4" "Ab4" 
"A4" "Bb4" "B4" "C5" "Db5" "D5" "Eb5" "E5" "F5" "Gb5" "G5" "Ab5" 
"A5" "Bb5" "B5" "C6" "Db6" "D6" "Eb6" "E6" "F6" "Gb6" "G6" "Ab6" 
"A6" "Bb6" "B6" "C7" "Db7" "D7" "Eb7" "E7" "F7" "Gb7" "G7" "Ab7" 
"A7" "Bb7" "B7" "C8"]

Edit: Changed from " "/""* to {8%}, to remove space.

edited Jul 28 '12 at 15:19

answered Jul 28 '12 at 15:09

Howard
6,3251822

I'm kind of intrigued by GolfScript, but a bit confused. Do you know of any tutorials that would help a beginner learn the language? I've tried the tutorial on the official GolfScript web site and looked at several other pages retrieved on Google, but it doesn't make a whole lot of sense. – Mike Dtrick Jul 28 '12 at 18:34

1

@MikeDtrick There are some Golfscript answers on this website that have explanations about how they work (e.g. codegolf.stackexchange.com/a/6058/3527). However, the best way to learn GS is to start coding something. Even better - try submitting a GS answer and you'll learn from the feedback you'll get :) – w0lf Jul 30 '12 at 15:25

1

@MikeDtrick other commented examples: codegolf.stackexchange.com/a/166/3527, codegolf.stackexchange.com/a/172/3527 – w0lf Jul 30 '12 at 15:26

@w0lf Thank you for the resources! – Mike Dtrick Jul 31 '12 at 19:41

@w0lf I know this probably isn't the proper place to ask a question, but I'm trying to code an answer for this question in GolfScript. I have a work in progress for the question, but I wanted to get in touch with someone who is skilled in this area. This is just practice, I won't post the answer if someone helps me out. Sorry for being a pest. – Mike Dtrick Aug 2 '12 at 0:57

show 1 more comment

Matt · Answer 3 · 2012-07-28 16:16:30Z

up vote 4 down vote

Python 103 96 94 78

[x+y for y in'0123456789'for x in'C Db D Eb E F Gb G Ab A Bb B'.split()][9:97]

updated according to Ev_genus's suggestion

updated according to Howard's suggestion

edited Jul 28 '12 at 16:16

answered Jul 28 '12 at 14:33

Matt
7028

94 [x+y for y in'0123456789'for x in['C','Db','D','Eb','E','F','Gb','G','Ab','A','Bb','B']][9:97] – Ev_genus Jul 28 '12 at 14:46

1

Maybe you can use 'C Db D Eb E F Gb G Ab A Bb B'.split()? – Howard Jul 28 '12 at 15:13

omg, really! 78 [x+y for y in'0123456789'for x in'C Db D Eb E F Gb G Ab A Bb B'.split()][9:97] – Ev_genus Jul 28 '12 at 15:26

@Howard yeah, i forgot about that – Matt Jul 28 '12 at 16:13

manatwork · Answer 4 · 2012-07-28 18:32:52Z

up vote 4 down vote

Ruby: 75 71 characters

[*?0..?9].product(%w{C Db D Eb E F Gb G Ab A Bb B}).map{|a,b|b+a}[9,88]

(Base idea borrowed from Matt's solution.)

edited Jul 28 '12 at 18:32

answered Jul 28 '12 at 17:07

manatwork
1,2611318

3

You can use [*?0..?9] which is a little shorter. – Howard Jul 28 '12 at 17:52

I felt that I am missing something there, but I completely forgot the splat. Thank you @Howard. – manatwork Jul 28 '12 at 18:35

David Carraher · Answer 5 · 2012-07-29 16:31:35Z

up vote 4 down vote

Mathematica 95 112 100 97 104 chars

Admittedly not very streamlined:

Take[Flatten@Table[# <> ToString@k & /@ 
Partition[Characters[" CDb DEb E FGb GAb ABb B"], 2], {k, 0, 8}], {10, 97}]

The Flat symbol, although it occupies a single character, is transcribed to SO as \[Flat] so I used the letter "b" here.

Output:

keys

Length@%
(* out *)
88

edited Jul 29 '12 at 16:31

answered Jul 28 '12 at 14:30

David Carraher
3,4291522

	How do you count 95 chars? – Matt Jul 28 '12 at 14:45
	I forgot to change the character count when I made a correction. It is now correct. (White spaces are there for legibility only, with the exception of those between quotes.) – David Carraher Jul 28 '12 at 14:57
	I get 100 keys from this rather than 88, but I can't find a rule against that, so +1 :-) – Mr.Wizard Jul 29 '12 at 14:15
	Weird. I too had noticed the 100 keys, but couldn't find an error. – David Carraher Jul 29 '12 at 14:21
	David, your comment made me look at this again. The output is no longer agreeing with the picture you included. It starts `"A0", "Bb0", " B0", " C0",` and furthermore `"C1"` doesn't occur until after "Db1", " D1"` etc. (Previously I thought the real keys were in order and there were extras interspersed.) Sorry, but it's broken. :-( – Mr.Wizard Jul 29 '12 at 16:10

show 1 more comment

Mr.Wizard · Answer 6 · 2012-07-29 13:31:47Z

up vote 3 down vote

Mathematica, 88

88 characters for 88 keys :-)

(Row@{#2,#1}&@@@Tuples@{0~Range~8,StringSplit@"C D♭ D E♭ E F G♭ G A♭ A B♭ B"})[[10;;97]]

answered Jul 29 '12 at 13:31

Mr.Wizard
1,17538

Gareth · Answer 7 · 2012-07-29 15:26:53Z

up vote 3 down vote

J, 81 76 63 62 61 58 characters

_11}.9}.(_2]\,|:9#"0'C DbD EbE F GbG AbA BbB '),.12#1":i.9

Output:

A 0 
Bb0 
B 0 
C 1 
Db1 
D 1 
Eb1 
E 1
...
G 7 
Ab7 
A 7 
Bb7 
B 7 
C 8

Probably a bit of room for shortening here.

edited Jul 29 '12 at 15:26

answered Jul 28 '12 at 13:44

Gareth
4,5751640

overcoder · Answer 8 · 2012-07-30 01:57:51Z

up vote 3 down vote

C (92 84 characters)

Not impressive, could be reduced further.

main(i){for(i=9;printf("%c%c%d\n","CDDEEFGGAABB"[i%12]," b b  b b b "[i%12],i/12),++i<97;);}

Using Dietrich Epp's suggestion :

main(i){for(i=9;printf("%.2s%d\n","C DbD EbE F GbG AbA BbB "+2*i%24,i/12),++i<97;);}

It produces the following output :

A 0
Bb0
B 0
C 1
Db1
D 1
Eb1
E 1
F 1
Gb1

... // lines skipped

Eb7
E 7
F 7
Gb7
G 7
Ab7
A 7
Bb7
B 7
C 8

edited Jul 30 '12 at 1:57

answered Jul 28 '12 at 17:04

overcoder
1312

	Can shave off 6 characters: `main(i){for(i=9;printf("%.2s%d\n","C DbD EbE F GbG AbA BbB "+(i%12)*2,i/12),++i<97;);}` – Dietrich Epp Jul 29 '12 at 0:02
	@DietrichEpp: Thanks! I shaved off two other characters. – overcoder Jul 30 '12 at 1:54

baby-rabbit · Answer 9 · 2012-07-29 02:58:14Z

C, 105 chars

- failing on size, so ended up aiming for a wtf different solution.

Probably only works on little-endian arch (e.g. intel) due to assumptions of treating int as small string... Assumes C program is called with no arguments, i.e. that w=1

t=12352,f;
main(w){
  t=t&64?t>>8:(w=1+w%7,(w-3)%3?t<<8|98:t+(w==3));
  f=t<<8|w+64;
  puts(&f);
  f-14403?main(w):0;
}

Output:

A0
Bb0
B0
C1
Db1
D1
Eb1
E1
F1
Gb1
G1
Ab1
--lines skipped--
Bb7
B7
C8

Edits

-9 chars - removing some brackets and reorganising an 'if'
-18 chars - code shuffling, sub 64 from w and pass as main arg
-13 chars - Use 't' to carry state rather than 'f'

PLL · Answer 10 · 2012-08-11 05:21:35Z

up vote 1 down vote

Haskell: 72 chars

take 88$drop 9[p++show o|o<-[0..],p<-words$"C D♭ D E♭ F F♯ G G♯ A B♭ B"]

answered Aug 11 '12 at 5:21

PLL
1214

kaoD · Answer 11 · 2012-08-12 03:45:50Z

up vote 1 down vote

Clojure - 71 chars

(for[c(range 10)n["C""Db""D""Eb""E""F""Gb""G""Ab""A""Bb""B"]](str n c))

answered Aug 12 '12 at 3:45

kaoD
34416

chinese perl goth · Answer 12 · 2012-10-18 22:11:22Z

up vote 0 down vote

Perl, 57+1

Just dug this up, a nice golfing exercise. Requires -E for say -- counted in score.

say+(CDbDEbEFGbGAbABbB=~/(.b?)/g)[$_%12],$_/12%9for 9..96

answered Oct 18 '12 at 22:11

chinese perl goth
27114

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Generate the names of the keys on a piano

12 Answers

Bash shell script (58)

GolfScript, 60 57 characters

Python 103 96 94 78

Ruby: 75 71 characters

Mathematica 95 112 100 97 104 chars

Mathematica, 88

J, 81 76 63 62 61 58 characters

C (92 84 characters)

C, 105 chars

- failing on size, so ended up aiming for a wtf different solution.

Edits

Haskell: 72 chars

Clojure - 71 chars

Perl, 57+1

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Generate the names of the keys on a piano

12 Answers

Bash shell script (58)

GolfScript, 60 57 characters

Python 103 96 94 78

Ruby: 75 71 characters

Mathematica 95 112 100 97 104 chars

Mathematica, 88

J, 81 76 63 62 61 58 characters

C (92 84 characters)

C, 105 chars

- failing on size, so ended up aiming for a wtf different solution.

Edits

Haskell: 72 chars

Clojure - 71 chars

Perl, 57+1

Your Answer

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