To determine how much time Colin spends practicing each song, we need to divide the total practice time by the number of songs.
Colin's total practice time is \( \frac{3}{4} \) of an hour, and he practices 6 songs.
To find the time spent on each song, we calculate:
\[ \text{Time per song} = \frac{\text{Total practice time}}{\text{Number of songs}} = \frac{\frac{3}{4}}{6} \]
We can rewrite the division as multiplication by the reciprocal:
\[ \text{Time per song} = \frac{3}{4} \times \frac{1}{6} \]
Now we multiply the fractions:
\[ \text{Time per song} = \frac{3 \times 1}{4 \times 6} = \frac{3}{24} \]
Next, we simplify \( \frac{3}{24} \):
\[ \frac{3}{24} = \frac{1}{8} \]
Thus, the fraction of an hour that Colin spends practicing each song is \( \frac{1}{8} \) of an hour.
The answer is: \[ \frac{1}{8} \text{ of an hour} \]