It's been suggested already, but the autoharp is the easiest and quickest to learn to be able to play the chords to familiar tunes. I taught my completely musically illiterate cousin to play one and she had a 'lightbulb' moment after about 2 weeks and is now quite an accomplished player. Leads worship at her church for different occasions. She started at age 40. She doesn't just strum the chords, either. She picks out melodies like Wildwood Flower and Silent Night. The autoharp is portable, playable and peaceful. A very intimate instrument in how it's played by holding it against one's chest. The technical facility required isn't very demanding, either. I highly recommend it. But, get the 21 key model as they are, usually better quality and have a greater variety of chords.