As you can see in the treble clef, the first half note is 2 beats, the last 4 eighth notes is 2 beats, which add up to 4 beats. There are only 4 beats in a bar, so where would the graces notes fit?
Even if I view them as something extra, I'm still confused as to how I can play the bar properly with a metronome.
Wow! That book must be really old because most editors would write that as a turn. Most editors would write it as the following
(I could not put a sharp in the turn. My software does not have the sharp turn)
Anyways, I would suggest playing those grace notes a little before beat three. If we are counting in sixteenth notes (1 e + a), starting on the 'a' would be the most natural. In other words, you would start playing the grace notes on the 'and' of the 'and' of beat 2 playing a triplet is pretty natural.
Doing so gives us this rhythm:
I hope that helps! Let me know if you need further clarification
I would usually play this with the 3 small notes as triplet semiquavers before the first quaver. But for some composers the 3 small notes should be played inside the first quaver, so those 4 notes are demisemiquavers. The earlier the music is, the more likely this is. Beethoven - before the quaver. Bach - on the quaver.
