I am surprised that there is no description for connecting the grove Speaker to Arduino (without the shield). Thanks for any help.
The Grove speaker can be seen on its pins in the picture above. He only needs to be connected to VCC - 3.3V, GND and a digital pin.
@Citrix kindly thanks! i connected SIG to Arduino Micro Digital4/Analog6.
the example ‘SpeakerTest’ from github (Seeed_Grove_Speaker_g) gets following output:
- 4 tones (same frequency)
- a chatter
- finally 1 tone (same frequency)
that seems to be more of a standard sequence or error message?
I have a few more questions to understand the Grove Speaker 
Regarding the Setup
const int pinSpeaker = A6;
- this setting defines the analog channel?
- change to A3,A4… has no effect (same sound, sup.)
- the channels A3,A4… are defined in the Arduino core?
Regarding Library/Sound generator
- NOTE_1 to NOTE_8 define the frequencies from 320 to 651 Hz in Speaker.h?
- in CodeCraft tones are defined as C3 through B5. This corresponds to the grading scale of music?
- the way Grove Speaker works is to generate sounds with certain frequencies.
With the setting of the time interval between the tones (delay), but without specifying the length of the tones, are only simple melodies producible?