Just thought I'd give a heads-up.
Even though WOW Airlines answers the question: "Can I travel with musical instruments? Of course you can. We love music!," be aware that unless you are traveling with a small parlor guitar, your Selmer/Maccaferri guitar will not be able to travel with you as a carry on.
Given WOW's low air fares, you might be tempted to book WOW to go overseas and tote your guitar to one of the various European Gypsy Jazz festivals. But unless you have a one of those carbon fiber cases that runs about $1000, you won't want to book WOW Airlines for you and your guitar.
At WOW, you can have a carry-on musical instrument if it fits within these dimension: 35.4" x 13.7" x 7.9". You can check yourself, but it's not likely that your gig bag (with your guitar nestled inside) fits within these dimensions.
Hope to see some of you at Festival Django Reinhardt, Fountainbleau/Samoreau!