# view
def music_add(request, music_id=None):
    if music_id is not None:
        operationType = "Alteração"
        music = get_object_or_404(Music, pk=music_id)
    else:
        operationType = "Cadastro"
        music = None
    { ... }
    if music_id:
        context = {'form':form, 'music_id':music_id, 'operationType':operationType,}
    else:
        context = {'form':form, 'operationType':operationType,}
    return render(request, 'repertory/music_add.html', context)

# template
<h2>{{ operationType }} de Música</h2>
{% if music_id %}
<form enctype="multipart/form-data" action="{% url 'repertory:music_edit' music_id %}" method="post">
{% else %}
<form enctype="multipart/form-data" action="{% url 'repertory:music_add' %}" method="post">
{ ... }