original: in the 1920s and early 1930s he frequently worked with the london symphony orchestra .
simplifications: in the 1920s and early 1930s he frequently worked with the london symphony orchestra . in the 1920s and early 1930s he constantlly worked with the london symphony orchestra . in the 1920s and early 1930s he often worked with the london symphony orchestra . in the 1920s and early 1930s he often worked with the london symphony orchestra . in the 1920s and early 1930s he regularly worked with the london symphony orchestra . in the 1920s and 1930s he frequently worked with the london symphony orchestra . in the 1920s and early 1930s , he often worked with the london symphony orchestra . in the 1920s and early 1930s he worked a lot with the london symphony orchestra .