What with the strange drum pad/note number layout?

I really don't know but apparently there is a reason. Here's a reference:

  Note number Layout

A

 

 

 

 

B

 

 

49

55

51

53

 

73

74

71

39

48

47

45

43

 

56

62

63

64

40

38

46

44

 

65

66

76

77

37

36

42

82

 

54

69

81

80

 

 

 

 

 

 

 

 

 

 

C

 

 

 

 

D

 

 

79

35

41

50

 

95

96

97

98

70

72

75

78

 

91

92

93

94

60

61

67

68

 

87

88

89

90

52

57

58

59

 

83

84

85

86

 

 

 

 

 

 

 

 

 

  Note Layout

A

 

 

 

 

B

 

 

C#3

G3

D#3

F3

 

C#5

D5

B4

D#2

C3

B2

A2

G2

 

G#3

D4

D#4

E4

E2

D2

A#2

G#2

 

F4

F#4

E5

F5

C#2

C2

F#2

A#5

 

F#3

A4

A5

G#5

 

 

 

 

 

 

 

 

 

 

C

 

 

 

 

D

 

 

D3

F2

B1

G5

 

B6

C7

C#7

D7

A#4

C4

D#4

F#4

 

G6

G#6

A6

A#6

C4

C#4

G4

G#4

 

D#6

E6

F6

F#6

E3

A3

A#3

B3

 

B5

C6

C#6

D6

 

 

 

 

 

 

 

 

 

  GM Layout

A

 

 

 

 

B

 

 

Crash Cymbal 1

Splash Cymbal

Ride Cymbal 1

Ride Cymbal Bell

 

Short Guiro

Long Guiro

Short Whistle

Hand Clap

Hi Mid Tom

Lo Mid Tom

Low Tom

High Floor Tom

 

Cowbell

Mute Hi Conga

Open Hi Conga

Low Conga

Electric Snare

Acoustic Snare

Open Hi Hat

Pedal Hi Hat

 

High Timbale

Low Timbale

Hi Woodblock

Lo Woodblock

Side Stick

Kick Drum 1

Closed Hi Hat

 

 

Tambourine

Cabasa

Open Triangle

Mute Triangle

 

 

 

 

 

 

 

 

 

 

C

 

 

 

 

D

 

 

Open Cuica

Acoustic Bass Drum

Low Floor Tom

High Tom

 

 

 

 

 

Maracas

Long Whistle

Claves

Mute Cuica