In opera and musical theatre, a "sitzprobe" (German for "seated rehearsal") is a rehearsal where singers and the orchestra rehearse together for the first time, focusing on the music and singing, usually without costumes or stage blocking. The primary goal of a sitzprobe is to integrate the singers and orchestra, allowing them to hear each other and work together musically. 

It usually occurs after the singers have rehearsed their parts individually or as a group with a pianist, and before tech rehearsals. While the term "sitzprobe" translates to "seated rehearsal," singers sometimes stand or move a bit during the rehearsal, especially as they work on musical dynamics and timing. 

A "wandelprobe" is similar, but the actors and singers are encouraged to move around on the stage while the band or orchestra plays. They still have to sing the parts they are assigned while moving.

A speed-through (or speed run) is a technical rehearsal technique where actors recite their lines as rapidly as possible, often sitting around a table without blocking, props, or costumes. Its purpose is to test line memorization, increase the show's overall pace, and sharpen cue pickup. It is sometimes called an "Italian," in reference to the perceived speed of fluent Italian speech.

• Goal: To eliminate unnecessary pauses, reinforce memory, and improve energy.\
• Method: Actors speak quickly but are often expected to maintain emotional connection.
• Timing: Usually performed in the final stages of rehearsals to tighten pacing before opening night.

It differs from a "stumble-through," which is a first run-through of a show , which is often rocky. 

The director is responsible for shaping every aspect of the final performance—from the actors' performances to the setting and design choices. Directors audition and cast actors; assemble and oversee the production team; provide design directives; lead rehearsals; and manage the production schedule of the project, ensuring that all the moving parts connect. They also supply a unifying understanding of the text and a particular vision for the production, which might mean a unique setting, a visual style or mood, or an interesting design concept that plays off themes in the text.

In opera and musical theatre, a “wandelprobe” is a musical rehearsal in which the actors and singers are free to move around on the stage while the band or orchestra plays. They still have to sing the parts they are assigned while moving.

The word "wandelprobe" comes from German and technically means "convertable trial," but in the theatre it translates as a "walking rehearsal." This sets it apart from a seated  rehearsal or "sitzprobe," where the focus is on giving the singers an opportunity to hear the full orchestra, and adjust their performance accordingly. It's sometimes referred to in the U.S. as a "wanderprobe," mostly due to a misunderstanding (or mispronunciation) of "wandel."

The movement in a “wandelprobe” isn't free-range wandering. The performers have to move to the approximate blocking for the production, if not the exact blocking, with the music’s tempo in mind.  There may be stops in order to work with the orchestra or band and the actors or singers in order to figure out how movements go together with the music.

A wandelprobe is usually held before tech starts and there usually are no lighting cues. However, everything is up to the decisions of the director and conductor. A wandelprobe (or even more than one wandelprobe) takes place before the first full dress rehearsal.