Listen for function, not fireworks
When reviewing a player’s work, ask whether the guitar improves the song. Does it support the vocal? Does it create movement without filling every space? Can the player sound simple when simple is what the record needs?
Range matters differently in the studio
Versatility is useful, but not because every player must imitate every genre. A strong session guitarist understands different rhythmic feels, tones, articulation and production conventions well enough to adapt without sounding generic.
Communication is part of musicianship
Can the player understand references, ask clarifying questions and explain what they are delivering? Remote sessions expose poor communication quickly because the producer cannot solve every misunderstanding in the room.
Technical delivery should be reliable
Correct sample rate, clean edits, sensible filenames and consolidated stems are not glamorous, but they determine whether the session saves the producer time or creates more work.
Look for judgment
Experienced session musicians know when not to play. They can identify that the useful part may be a single texture in the second verse rather than another full rhythm track. That judgment becomes more valuable as arrangements become denser.
Decide whether you need a player or a collaborator
If you know every note and only need execution, hire for accuracy and sound. If the part itself still needs to be invented, hire someone whose arrangement instincts and musical history you trust.
Next step
If this is the problem you are trying to solve in a current song, you do not need to wait until the project is polished. Send Sven the demo and explain where the decision feels unclear.