aubio.notes works incorrectly (Python)

Question

I need to recognize notes from melody, so I used this demo code:

#! /usr/bin/env python

import sys
from aubio import source, notes

if len(sys.argv) < 2:
    print("Usage: %s <filename> [samplerate]" % sys.argv[0])
    sys.exit(1)

filename = sys.argv[1]

downsample = 1
samplerate = 44100 // downsample
if len( sys.argv ) > 2: samplerate = int(sys.argv[2])

win_s = 512 // downsample # fft size
hop_s = 256 // downsample # hop size

s = source(filename, samplerate, hop_s)
samplerate = s.samplerate

tolerance = 0.8

notes_o = notes("default", win_s, hop_s, samplerate)

print("%8s" % "time","[ start","vel","last ]")

# total number of frames read
total_frames = 0
while True:
    samples, read = s()
    new_note = notes_o(samples)
    if (new_note[0] != 0):
        note_str = ' '.join(["%.2f" % i for i in new_note])
        print("%.6f" % (total_frames/float(samplerate)), new_note)
    total_frames += read
    if read < hop_s: break

https://github.com/aubio/aubio/blob/master/python/demos/demo_notes.py

And first note in melody not determining correctly. So, i made C major musical scale and programm printed me, that the first note is Am (But it must be C). But the funniest is that the other notes are correct. My output:

    time [ start vel last ]
0.029025 [ 64. 108.  -1.]
0.516644 [ 47. 106.  64.]
0.975238 [ 49. 109.  47.]
1.439637 [ 50. 106.  49.]
1.898231 [ 52. 108.  50.]
2.362630 [ 54. 109.  52.]
2.821224 [ 56. 109.  54.]
3.285624 [ 57. 108.  56.]

First number in lists is a code for MIDI note. How could I fix it?