**4. Self-Organization and Collective Bands in Heavy Nuclei**

We now proceed to more general cases of the monopole–quadrupole interplay. This interplay leads to unexpected consequences in the underlying mechanism of collective bands of heavy nuclei [71], beyond the standard textbooks.

The MCSM has become powerful enough [62] to reproduce collective bands of heavy nuclei such as 154Sm and 166Er, with one and half HO major shells [71]. We sketch the new findings by using the results of such most-advanced MCSM calculations.
