| | 490 | <sect2 id="taptempo"> |
| | 491 | <title>Tap Tempo and BeatCounter</title> |
| | 492 | |
| | 493 | <para>It is possible to change tempo at any time using |
| | 494 | the tap-tempo and BeatCounter features of Hydrogen. You |
| | 495 | can change these while playing or while the song is |
| | 496 | stopped. To change the tempo, hit |
| | 497 | the <keycap>,</keycap> (comma) key in tempo for the |
| | 498 | number of beats in the measure. After the correct |
| | 499 | number of beats are met, the tempo will change to the |
| | 500 | average tempo that you tapped in. If you continue to |
| | 501 | tap, these new taps will become a part of a rolling |
| | 502 | average. If you tap accidentally, or if you wait too |
| | 503 | long between taps, the tap tempo counter will start |
| | 504 | over.</para> |
| | 505 | |
| | 506 | <para>The Tap Tempo is a part of the BeatCounter, which |
| | 507 | is essentially a Tap Tempo on steroids. By default the |
| | 508 | BeatCounter display is not visible. To see the |
| | 509 | BeatCounter widget click the upright button |
| | 510 | (<guilabel>BC</guilabel>) between Song/Pattern mode |
| | 511 | selector and the BPM-widget. Or, it can be shown by |
| | 512 | pressing the comma key (<keycap>,</keycap>).</para> |
| | 513 | |
| | 514 | <para>The tempo that you tap will be considered even |
| | 515 | beats of the beat type. The beat type can be set to 1/8 |
| | 516 | (for eight-note beats), 1/4 (for quarter-note beats), |
| | 517 | 1/2 (for half-note beats), and 1/1 (for whole-note |
| | 518 | beats). To change the beat type use the left arrow |
| | 519 | buttons. To change the number of beats that are |
| | 520 | counted, use the right arrow button. You can set from 2 |
| | 521 | to 16 beats. (I.e. if you set the beat to 6, you will |
| | 522 | have to tap 6 times before the new tempo is computed and |
| | 523 | set.) When the display shows an <guilabel>R</guilabel>, |
| | 524 | it means that the BeatCounter is ready to start from 0. |
| | 525 | Every time you tap with the comma key, it will show the |
| | 526 | number of taps that you have entered (1, 2, |
| | 527 | 3...).</para> |
| | 528 | |
| | 529 | <para>The button in the bottom right-hand controls the |
| | 530 | auto-start feature, and it toggles |
| | 531 | between <guilabel>S</guilabel> |
| | 532 | and <guilabel>P</guilabel>. When it |
| | 533 | shows <guilabel>P</guilabel> for |
| | 534 | (<emphasis>Play</emphasis>), the song will set the new |
| | 535 | tempo and automatically start to play after you tap the |
| | 536 | right number of beats (if it's not already playing, of |
| | 537 | course). This way, if you have the BeatCounter set up |
| | 538 | for 4/4, you can tap 1-2-3-4, and start playing on the |
| | 539 | next beat. When it shows <guilabel>S</guilabel> |
| | 540 | (for <emphasis>Set BPM</emphasis>), the auto-start is |
| | 541 | disabled.</para> |
| | 542 | |
| | 543 | <para>For example: Suppose you have a live band, |
| | 544 | Hydrogen, and a softsynth that is controlled by |
| | 545 | Seq24)... and you want them all to start at the same |
| | 546 | time. Set the beat type to 1/4 and the number of beats |
| | 547 | to 4. Enable auto-start (button |
| | 548 | shows <guilabel>P</guilabel>). Count off the band |
| | 549 | 1-2-3-4 (while tapping the comma key) — and |
| | 550 | everyone starts on 1.</para> |
| | 551 | |
| | 552 | <para>Another example: Same situation, but the song |
| | 553 | doesn't require Hydrogen or synths until some point |
| | 554 | later. During that time, a human (e.g. guitar player) |
| | 555 | will be setting the tempo. On the measure before |
| | 556 | Hydrogen is supposed to play, tap the comma key 1-2-3-4 |
| | 557 | with the beat... and you're in on the next beat (at the |
| | 558 | right tempo).</para> |
| | 559 | |
| | 560 | <para>If you are using the JACK Transport, the |
| | 561 | BeatCounter continues to work. If another program is |
| | 562 | the JACK Transport Master, Hydrogen will respond to |
| | 563 | tempo change events from that application. Note that in |
| | 564 | this situation, Hydrogen is supposed to be |
| | 565 | a <emphasis>slave</emphasis>, so some of the BeatCounter |
| | 566 | features will be disabled or will not work properly. If |
| | 567 | Hydrogen is the JACK Transport Master, tempo changes |
| | 568 | from Hydrogen will be reflected in those programs (if |
| | 569 | they support it).</para> |
| | 570 | |
| | 571 | <para>Some of the settings to adjust the BeatCounter's |
| | 572 | latency compensation, and they are located on the |
| | 573 | <guilabel>General</guilabel> tab of the Preferences |
| | 574 | Dialog ( |
| | 575 | |
| | 576 | <menuchoice> |
| | 577 | <guimenu>Tools</guimenu> |
| | 578 | <guimenuitem>Preferences</guimenuitem> |
| | 579 | </menuchoice> |
| | 580 | |
| | 581 | ). Here there are two spinboxes:</para> |
| | 582 | |
| | 583 | <itemizedlist> |
| | 584 | <listitem><para><emphasis role="bold"><guilabel>Beat |
| | 585 | counter drift compensation in |
| | 586 | 1/10ms</guilabel></emphasis> — adjust to |
| | 587 | compensate for latency between the keyboard and |
| | 588 | the program.</para></listitem> |
| | 589 | |
| | 590 | <listitem><para><emphasis role="bold"><guilabel>Beat |
| | 591 | counter start offset in ms</guilabel></emphasis> |
| | 592 | — adjust the time between the |
| | 593 | BeatCounter's last input stroke and when the |
| | 594 | song starts playing (if auto-start is |
| | 595 | activated).</para></listitem> |
| | 596 | </itemizedlist> |
| | 597 | |
| | 598 | <para>Note that these can be set to positive (+) or |
| | 599 | negative (-) values. In order to find useful values for |
| | 600 | these, you will need to take some time to play with it. |
| | 601 | Also, you may want different values depending on the |
| | 602 | speed of your hardware, audio devices, drivers, etc. |
| | 603 | Using the BeatCounter effectively requires |
| | 604 | practice.</para> |
| | 605 | |
| | 606 | </sect2> |
