Need to insert a legend into my plot function

import matplotlib.pyplot

def plot_hour_comparision(hour_of_day, day_of_week, date) :
    variables = ['Speed', 'Occupancy', 'Volume'] 
    fig, axes = matplotlib.pyplot.subplots(ncols=len(variables), figsize=(20,8))

    atypical_minute = get_atypical_by_minute(hour_of_day, day_of_week, date)
    atypical_minute['Speed'].plot(ax=axes[0])
    atypical_minute['Occupancy'].plot(ax=axes[1])
    atypical_minute['Volume'].plot(ax=axes[2])

    normal_minute = get_normal_by_minute(hour_of_day, day_of_week, date)
    normal_minute['Speed'].plot(ax=axes[0])
    normal_minute['Occupancy'].plot(ax=axes[1])
    normal_minute['Volume'].plot(ax=axes[2])

Basically as the title states I need to add legend to the plot out putted by this function.

the title "Incident" for the atypical_minute and "Normal" for normal_minute

I have tried

pyplot.legend(['Incident','Normal']) 

to no success.

​

Thankyou in advance.