前言
在前面三篇文章中,我介紹瞭如何通過Python的Mido庫添加旋律、和絃和模擬滑音、顫音。然而,鼓的作用也是不可忽視的,它就像骨骼一樣支撐起整個音樂,而編輯鼓點的樣式也爲想象力的發揮提供了無限空間,是十分愉悅的事情,本篇文章我就介紹如何向MIDI文件中添加鼓的音軌。
專屬頻道
同其他樂器不同,MIDI格式爲鼓組提供了專屬的頻道,默認在10號頻道,並在這個頻道的40多個音符對應處替換上了不同種類的鼓點樣式,爲了更方便調用,我做成了一個函數,以供參考:
def get_drum_dict():
drum_dict = {
'acoustic_bass': 35,
'bass1': 36,
'side_stick': 37,
'acoustic_snare': 38,
'hand_clap': 39,
'electric_snare': 40,
'low_floor_tom': 41,
'closed_hi-hat': 42,
'high_floor_tom': 43,
'pedal_hi-hat': 44,
'low_tom': 45,
'open_hi-hat': 46,
'low-mid_tom': 47,
'hi-mid_tom': 48,
'crash_cymbal1': 49,
'high_tom': 50,
'ride_cymbal1': 51,
'chinese_cymbal': 52,
'ride_bell': 53,
'tambourine': 54,
'splash_cymbal': 55,
'cowbell': 56,
'crash_cymbal2': 57,
'vibraslap': 58,
'ride_cymbal2': 59,
'hi_bongo': 60,
'low_bongo': 61,
'mute_hi_bongo': 62,
'open_hi_bongo': 63,
'low_conga': 64,
'high_timbale': 65,
'low_timbale': 66,
'high_agogo': 67,
'low_agogo': 68,
'cabasa': 69,
'maracas': 70,
'short_whistle': 71,
'long_whistle': 72,
'short_guiro': 73,
'long_guiro': 74,
'claves': 75,
'hi_wood_block': 76,
'low_wood_block': 77,
'mute_cuica': 78,
'open_cuica': 79,
'mute_triangle': 80,
'open_triangle': 81
}
return drum_dict
可見從35到81全是對應的鼓的樣式,對普通編曲而言肯定是夠了。
編程實現
有了專屬的頻道,那麼我們就能夠很輕鬆地來創作自己的鼓組音軌了,爲了方便我寫了一個添加鼓點的函數,供大家參考:
def add_drum(name, time, track, delay=0, velocity=1):
bpm = get_bpm(track)
meta_time = 60 * 60 * 10 / bpm
drum_dict = get_drum_dict()
try:
note = drum_dict[name]
except:
print(traceback.format_exc())
return
track.append(Message('note_on', note=note, velocity=round(64 * velocity), time=delay, channel=9))
track.append(
Message('note_off', note=note, velocity=round(64 * velocity), time=round(meta_time * time), channel=9))
爲了讓自己的鼓點更加豐富一點,我添加了兩個鼓的音軌,一個用於踩鑔(Hi-Hat),主要是用於基本節奏的把握,另一個是軍鼓(Snare)、嗵鼓(Tom)和強音鈸(Crash Cymbal),用於使節奏更加Funky和Groovy,並在其他樂器空白間隙加入過門,使得音樂更加豐滿。
- 首先是鑔軌,我編寫得十分簡單:
def hi_hat(track):
for i in range(8):
add_drum('open_hi-hat', 0.5, track, velocity=0.6)
add_drum('closed_hi-hat', 0.5, track, velocity=0.6)
add_drum('closed_hi-hat', 0.5, track, velocity=0.6)
add_drum('open_hi-hat', 0.5, track, velocity=0.6)
add_drum('closed_hi-hat', 0.5, track, velocity=0.6)
add_drum('closed_hi-hat', 0.5, track, velocity=0.6)
for i in range(16):
add_drum('open_hi-hat', 0.5, track, velocity=0.6)
add_drum('closed_hi-hat', 0.25, track, velocity=0.6)
add_drum('closed_hi-hat', 0.25, track, velocity=0.6)
add_drum('closed_hi-hat', 0.25, track, velocity=0.6)
add_drum('closed_hi-hat', 0.25, track, velocity=0.6)
add_drum('open_hi-hat', 0.5, track, velocity=0.6)
add_drum('closed_hi-hat', 0.5, track, velocity=0.6)
add_drum('closed_hi-hat', 0.5, track, velocity=0.6)
- 然後是玩花兒的軌,我用了兩個函數來實現:
def tom_and_snare_pt1(track):
for i in range(7):
add_drum('acoustic_snare', 0.5, track, velocity=0.8)
add_drum('low_tom', 0.5, track, velocity=0.6)
add_drum('low-mid_tom', 0.5, track, velocity=0.6)
add_drum('acoustic_snare', 0.5, track, velocity=0.6)
add_drum('low_tom', 0.25, track, velocity=0.8)
add_drum('acoustic_snare', 0.5, track, velocity=0.8)
add_drum('low-mid_tom', 0.25, track, velocity=0.6)
add_drum('acoustic_snare', 0.5, track, velocity=0.8)
add_drum('low_tom', 0.25, track, velocity=0.6)
add_drum('low-mid_tom', 0.25, track, velocity=0.6)
add_drum('acoustic_snare', 0.25, track, velocity=0.8)
add_drum('acoustic_snare', 0.125, track, velocity=0.8)
add_drum('acoustic_snare', 0.125, track, velocity=0.8)
add_drum('acoustic_snare', 0.25, track, velocity=0.8)
add_drum('acoustic_snare', 0.25, track, velocity=0.8)
add_drum('crash_cymbal1', 0.25, track, velocity=1.2)
add_drum('acoustic_snare', 0.25, track, velocity=0.8)
add_drum('crash_cymbal2', 0.25, track, velocity=1.2)
add_drum('acoustic_snare', 0.25, track, velocity=0.8)
def tom_and_snare_pt2(track, num):
for i in range(3): #6
add_drum('acoustic_snare', 0.25, track, velocity=0.8)
add_drum('acoustic_snare', 0.25, track, velocity=0.8)
add_drum('low_tom', 0.5, track, velocity=0.6)
add_drum('high_tom', 0.25, track, velocity=0.6)
add_drum('low-mid_tom', 0.25, track, velocity=0.6)
add_drum('acoustic_snare', 0.5, track, velocity=0.6)
add_drum('low_tom', 0.25, track, velocity=0.8)
add_drum('acoustic_snare', 0.5, track, velocity=0.9)
add_drum('low-mid_tom', 0.125, track, velocity=0.6)
add_drum('hi-mid_tom', 0.125, track, velocity=0.6)
add_drum('acoustic_snare', 0.5, track, velocity=0.8)
add_drum('low_tom', 0.25, track, velocity=0.6)
add_drum('low-mid_tom', 0.25, track, velocity=0.6)
add_drum('high_tom', 0.25, track, velocity=0.6)
add_drum('low-mid_tom', 0.25, track, velocity=0.6)
add_drum('acoustic_snare', 0.125, track, velocity=0.8)
add_drum('acoustic_snare', 0.125, track, velocity=0.8)
add_drum('acoustic_snare', 0.125, track, velocity=0.8)
add_drum('acoustic_snare', 0.125, track, velocity=0.8)
add_drum('crash_cymbal1', 0.25, track, velocity=1.2)
add_drum('high_tom', 0.25, track, velocity=0.6)
add_drum('crash_cymbal2', 0.25, track, velocity=1.2)
add_drum('low-mid_tom', 0.25, track, velocity=0.6)
add_drum('acoustic_snare', 0.5, track, velocity=0.8)
add_drum('low_tom', 0.25, track, velocity=0.6)
add_drum('low-mid_tom', 0.25, track, velocity=0.6)
add_drum('acoustic_snare', 0.25, track, velocity=0.8)
add_drum('acoustic_snare', 0.125, track, velocity=0.8)
add_drum('acoustic_snare', 0.125, track, velocity=0.8)
add_drum('acoustic_snare', 0.25, track, velocity=0.8)
add_drum('acoustic_snare', 0.25, track, velocity=0.8)
add_drum('crash_cymbal1', 0.25, track, velocity=1.2)
add_drum('acoustic_snare', 0.25, track, velocity=0.8)
add_drum('crash_cymbal2', 0.25, track, velocity=1.2)
add_drum('acoustic_snare', 0.25, track, velocity=0.8)
add_drum('high_tom', 0.125, track, velocity=0.9)
add_drum('high_tom', 0.125, track, velocity=0.9)
add_drum('hi-mid_tom', 0.125, track, velocity=0.9)
add_drum('hi-mid_tom', 0.125, track, velocity=0.9)
add_drum('low-mid_tom', 0.125, track, velocity=0.9)
add_drum('low-mid_tom', 0.125, track, velocity=0.9)
add_drum('low_tom', 0.125, track, velocity=0.9)
add_drum('low_tom', 0.125, track, velocity=0.9)
add_drum('high_floor_tom', 0.25, track, velocity=1.1)
add_drum('high_floor_tom', 0.25, track, velocity=1.1)
add_drum('low_floor_tom', 0.25, track, velocity=1.2)
add_drum('low_floor_tom', 0.25, track, velocity=1.2)
if num == 1:
add_drum('crash_cymbal1', 0.25, track, velocity=1.2)
add_drum('crash_cymbal2', 0.25, track, velocity=1.2)
add_drum('crash_cymbal1', 0.25, track, velocity=1.2)
add_drum('crash_cymbal2', 0.25, track, velocity=1.2)
if num == 2:
add_drum('low_floor_tom', 0.25, track, velocity=1.3)
add_drum('low_floor_tom', 0.25, track, velocity=1.3)
add_drum('chinese_cymbal', 1, track, velocity=1.9)
鼓組音軌的MIDI文件可參考 drum.mid
完整項目可參考 Github - Truedick23/MusicCritique