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Synthesizers, Music & Television © T. Yahaya Abdullah

## Composition Tools

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### Terms Used

• Tempo - Speed of music; measured in "bpm"
• bpm - Beats per minute; usually 4 beats to a "bar"
• Length - Length of music segment; measured in "bars"
• Time - Duration of music segment

### Tempo (bpm) Calculations

The relationship between Tempo, Time and Length is quite simple. Basically, Length = Tempo x Time. The difficulty arises because of the different units of mesurement used.
- Tempo is in beats per minute (bpm).
- Length is in bars (not beats).
- Time is in seconds (not minutes).
As such, the easiest way to resolve the problem is to introduce a constant of 240 (ie 60 seconds per minute x 4 beats per bar). This normalises the equation as follows:-

(BARS x 240) = BPM x SECONDS

For LENGTH in Bars,

BARS = (BPM x SECONDS) / 240

For TEMPO in bpm,

BPM = (BARS x 240) / SECONDS

For TIME in seconds,

SECONDS = (BARS x 240) / BPM

Time is a critical factor when composing music for commercial use. As such, I have provided a table below which gives Tempo settings for 20, 30 and 40 seconds. For example, to achieve 18 seconds in 9 bars requires a tempo of 120bpm.

 bpm Bars Seconds 4 5 6 7 8 9 10 11 12 13 14 16 60.0 75.0 90.0 105.0 120.0 135.0 150.0 165.0 180.0 195.0 210.0 17 56.5 70.6 84.7 98.8 112.9 127.1 141.2 155.3 169.4 183.5 197.6 18 53.3 66.7 80.0 93.3 106.7 120.0 133.3 146.7 160.0 173.3 186.7 19 50.5 63.2 75.8 88.4 101.1 113.7 126.3 138.9 151.6 164.2 176.8 20 48.0 60.0 72.0 84.0 96.0 108.0 120.0 132.0 144.0 156.0 168.0 Seconds 9 10 11 12 13 14 15 16 17 18 19 26 83.1 92.3 101.5 110.8 120.0 129.2 138.5 147.7 156.9 166.2 175.4 27 80.0 88.9 97.8 106.7 115.6 124.4 133.3 142.2 151.1 160.0 168.9 28 77.1 85.7 94.3 102.9 111.4 120.0 128.6 137.1 145.7 154.3 162.9 29 74.5 82.8 91.0 99.3 107.6 115.9 124.1 132.4 140.7 149.0 157.2 30 72.0 80.0 88.0 96.0 104.0 112.0 120.0 128.0 136.0 144.0 152.0 Seconds 14 15 16 17 18 19 20 21 22 23 24 36 93.3 100.0 106.7 113.3 120.0 126.7 133.3 140.0 146.7 153.3 160.0 37 90.8 97.3 103.8 110.3 116.8 123.2 129.7 136.2 142.7 149.2 155.7 38 88.4 94.7 101.1 107.4 113.7 120.0 126.3 132.6 138.9 145.3 151.6 39 86.2 92.3 98.5 104.6 110.8 116.9 123.1 129.2 135.4 141.5 147.7 40 84.0 90.0 96.0 102.0 108.0 114.0 120.0 126.0 132.0 138.0 144.0

### Delay Calculations

The same equation (as above) can be used to calculate delay times. However, digital delay times are quoted in milliseconds so the equation has to be altered a bit.
For TIME in milliseconds,

MilliSeconds = (BARS x 240,000) / BPM

So to work out the delay-time for 3 sixteenths of a bar would be,
((240,000 x 3) / 16) / BPM
which equals to 45,000 / BPM. Assuming the tempo is 120bpm, the delay time for 3/16 of a bar would be
45,000 / 120 = 375 milliseconds.

The table below lists the various delay times in milliseconds for 16ths of a bar and 12ths of a bar.

 Time (ms) Sixteenths of a Bar Twelfths of a Bar bpm 1 2 3 4 5 6 7 8 1 2 4 5 60 250 500 750 1000 1250 1500 1750 2000 333 667 1333 1667 65 231 462 692 923 1154 1385 1615 1846 308 615 1231 1538 70 214 429 643 857 1071 1286 1500 1714 286 571 1143 1429 75 200 400 600 800 1000 1200 1400 1600 267 533 1067 1333 80 188 375 563 750 938 1125 1313 1500 250 500 1000 1250 85 176 353 529 706 882 1059 1235 1412 235 471 941 1176 90 167 333 500 667 833 1000 1167 1333 222 444 889 1111 95 158 316 474 632 789 947 1105 1263 211 421 842 1053 100 150 300 450 600 750 900 1050 1200 200 400 800 1000 105 143 286 429 571 714 857 1000 1143 190 381 762 952 110 136 273 409 545 682 818 955 1091 182 364 727 909 115 130 261 391 522 652 783 913 1043 174 348 696 870 bpm 1/16 1/8 3/16 1/4 5/16 3/8 7/16 1/2 1/12 1/6 1/3 5/12 120 125 250 375 500 625 750 875 1000 167 333 667 833 125 120 240 360 480 600 720 840 960 160 320 640 800 130 115 231 346 462 577 692 808 923 154 308 615 769 135 111 222 333 444 556 667 778 889 148 296 593 741 140 107 214 321 429 536 643 750 857 143 286 571 714 145 103 207 310 414 517 621 724 828 138 276 552 690 150 100 200 300 400 500 600 700 800 133 267 533 667 155 97 194 290 387 484 581 677 774 129 258 516 645 160 94 188 281 375 469 563 656 750 125 250 500 625 165 91 182 273 364 455 545 636 727 121 242 485 606 170 88 176 265 353 441 529 618 706 118 235 471 588 175 86 171 257 343 429 514 600 686 114 229 457 571 180 83 167 250 333 417 500 583 667 111 222 444 556

### Rhyme Chart

Here's a simple chart to help with rhyming. Basically you take the last syllable of a word and try starting the syllable with each of the letters in the chart.

For example, if you were trying to rhyme with "orange", the last syllable would be "..ange". Going through the chart, you'd come up with "range", "change" and "strange".

 R L H J N V M B BR BL C CR CL CH CHR D DR F FR FL G GR GL GN K KR KL KN QU P PR PL PH S SL SH SHR SW SM SC SCR SK SP SPR SPL SN ST STR T TR TH THR TW W WR WH Y X Z A E I O U