Highlighting Column B and running this VBA should do the trick:
Sub bandsplit()
Dim c As Range
Dim splitv() As String
For Each c In Selection
splitv = Split(c.Value, "/")
If UBound(splitv) > 0 Then
c.EntireRow.Insert
c.Offset(-1, 0).Value = splitv(1)
c.Offset(-1, -1).Value = c.Offset(0, -1).Value
c.Value = splitv(0)
End If
Next c
End Sub
It's restricted to 2 genres but you could hack it to add more.
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