Step 1: Concept
Janya (derivative) ragas are structurally classified by the arrangement of notes in their scales.
Step 2: Vakra Ragas
- Definition: A Janya raga where the notes in the ascending or descending scale do not progress in a straight, linear sequence, but instead take a crooked, zig-zag path, looping back to a previous note before moving forward.
- Example: Reethigoula (derived from Kharaharapriya). Its Arohana scale is Vakra: $S\ G_2\ R_2\ G_2\ M_1\ N_2\ D_2\ M_1\ N_2\ N_2\ S$.
Step 3: Varja Ragas
- Definition: A Janya raga where one, two, or three notes of the parent Melakarta scale are completely omitted (deleted) in either the ascent, the descent, or both.
- Classification: Omitting 1 note = Shadava (6-note); Omitting 2 notes = Audava (5-note).
- Example: Mohanam (derived from Harikambhoji). It is an Audava raga that completely omits Madhyama ($M$) and Nishada ($N$). Scale: $S\ R_2\ G_3\ P\ D_2\ S$ $S\ D_2\ P\ G_3\ R_2\ S$.
Final Answer: A Vakra raga has a crooked, zig-zag arrangement of notes in its scale (e.g., Reethigoula), while a Varja raga completely omits one or more notes from its parent scale (e.g., Mohanam).