Ariana Grande is taking a big step forward … moving on from the terrorist attack at her Manchester concert last year by completing her 4th album, which we’re told is a “personal” masterpiece.

Sources close to the singer tell TMZ … she just played the entire album at a wrap meeting with Republic Records execs and her manager, Scooter Braun, and everyone’s raving — it’s her best yet.

We’re told half of the album was produced by Pharrell and the other half by Max Martin, but Ariana was involved in the writing of every song … something new for her.

Grande posted a pic of Friday’s meeting as a teaser, although it’s unclear at this point when the album will be released. We’re told the next step is working on visuals and album art.

As we reported … Ariana’s Manchester show was rocked by an explosion last May, leaving 22 people dead. However, Ariana spearheaded the One Love Manchester Benefit Concert just 2 weeks later to raise money for victims. [TMZ]