We present examples of an extended asteroseismic modelling in which we aim at fitting not only pulsational frequencies but also certain complex parameter related to each frequency. This kind of studies, called textbf{complex asteroseismology}, has be
en successfully applied to a few main sequence B-type pulsators and provided, in particular, plausible constraints on textbf{stellar opacities}. Here, we briefly describe our results for three early B-type stars.
During the last few decades, great effort has been made towards understanding hydrodynamical processes which determine the structure and evolution of stars. Up to now, the most stringent constraints have been provided by helioseismology and stellar c
luster studies. However, the contribution of asteroseismology becomes more and more important, giving us an opportunity to probe the interiors and atmospheres of very different stellar objects. A variety of pulsating variables allows us to test various parameters of micro- and macrophysics by means of oscillation data. I will review the most outstanding key problems, both observational and theoretical, of which our knowledge can be improved by means of asteroseismology.
I discuss a prospect for mode identification from two-passband photometry of forthcoming BRITE space mission. Examples of photometric diagnostic diagrams are shown for three types of main sequence pulsating variables: $beta$ Cephei, Slowly Pulsating
B-type and $delta$ Scuti stars. I consider also taking into account the radial velocity data from simultaneous spectroscopy, which can be carried out from the ground. With such observations, much better discrimination of the spherical harmonic degree, $ell$, can be accomplished and more constraints on stellar parameters and input physics can be derived.
