Anniversary Of Clara Rockmore

1. She invented it into the past so we have to use the past tense, so it "was" invented.

2. There are several ways to phrase the instruments she played with her age, for example:

By the age of 4, Clara played the piano and violin

Aged 4, Clara (already) played the piano and violin 

as well as the correction I have made to your writing above!

3. "Most young" conveys the meaning here but it is not how a native speaker would phrase it. "Youngest" is called the superlative. You can google it for more examples! It is how we usually compare adjective in English although there are irregularities. Young is the adjective, younger is the comparitive and youngest is superlative.

4. Be careful of he endings for 3rd person singular in the present tense. Verbs end in an -s :) e.g. allows, interrupts

Hope this helps and wasn't too complicated! :)

Anniversary Of Clara Rockmore

Today is the anniversary/birthday of Clara Rockmore. The woman that made her famoud a Theremin famous.
The Theremin was invented by Léon Theremin. Clara played the piano and violin at age 4 years of age old and she was the most youngest person that to be admitted at the Conservatory of San Pietroburgo.
The Theremin is an instrumental that allow to modifies the sound depending on the position of the hands. It interrupts the electromagnetic field that is generated.