在前面三篇文章中,我介绍了如何通过Python的Mido库添加旋律、和弦和模拟滑音、颤音。然而,鼓的作用也是不可忽视的,它就像骨骼一样支撑起整个音乐,而编辑鼓点的样式也为想象力的发挥提供了无限空间,是十分愉悦的事情,本篇文章我就介绍如何向MIDI文件中添加鼓的音轨。
同其他乐器不同,MIDI格式为鼓组提供了专属的频道,默认在10号频道,并在这个频道的40多个音符对应处替换上了不同种类的鼓点样式,为了更方便调用,我做成了一个函数,以供参考:
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
可见从35到81全是对应的鼓的样式,对普通编曲而言肯定是够了。
有了专属的频道,那么我们就能够很轻松地来创作自己的鼓组音轨了,为了方便我写了一个添加鼓点的函数,供大家参考:
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))
为了让自己的鼓点更加丰富一点,我添加了两个鼓的音轨,一个用于踩镲(Hi-Hat),主要是用于基本节奏的把握,另一个是军鼓(Snare)、嗵鼓(Tom)和强音钹(Crash Cymbal),用于使节奏更加Funky和Groovy,并在其他乐器空白间隙加入过门,使得音乐更加丰满。
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)
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)
鼓组音轨的MIDI文件可参考 drum.mid
完整项目可参考 Github - Truedick23/MusicCritique