Most of the advantages of NTFS for associated volumes (ie not your boot drive on a computer) are irrelevant in small sized volumes like flash drives. Many of those advantages become disadvantages when you are dealing with a small, highly portable storage device like a flash drive.
NTFS's upport for ACL (advanced file permissions) will limit the easy portability of flash drives from device to device, and can even impact portability from Windows computer to Windows computer.
Most flash drives have their own volume mapping tools built-in ... a flash drive is not like a HD where you can expect to re-write the same area many, many times, so flash drives force new data and re-writes to unused or under-used areas of the drive ... so the NTFS logging and journaling features are also not really necessary. This also makes NTFS's volume resizing features useless.
NTFS's Alternate Data Streams again are not really needed on a flash media where the data is going to be directly read by a music player or graphics program directly. Since some malware uses ADS to hide code, in a highly portable file system like a flash drive, it can be seen as a possible disadvantage.
Nobody really uses a flash drive to store huge databases, so NTFS's Sparse file support isn't needed.
NTFS's compression support isn't helpful unless the data is repetitive and accessed sequentially (i.e., not useful for music or graphics). Also, if NTFS's compression support is applied to already compressed files, like FLAC, it slows down retrieval, which can be an issue with real-time music data. It also puts heavier loads on the host's CPU and power requirements.
NTFS's support for Encrypted File Systems, Disk Quotas, Reparse Points, Volume mount points, Directory junctions, Symbolic links, Single Instance Storage, Hierarchical Storage Management and Native Structure Storage (no longer supported in modern versions of Windows) all have no earthly use in a portable flash drive of music files used with multiple devices, when some of those devices are not Windows OS computers.
The NTFS default cluster size is 4 kB, although up to 64 kB options are available. FAT32 cluster size varies; NTFS has an advantage here if the drive is at least 8 GB in size. (It is unlikely that an audio file would exceed FAT32's maximum file size of 4GB, so NTFS's maximum of 16 Excabytes is not really an issue).
Provided you robustly back up the NTFS-formatted flash drive on a hard drive on a Windows NT-derived OS (XP or newer) data may be more recoverable with NTFS. However, FAT32 does not prevent you from backing up your media files.
Practically speaking, consumers are more likely to use backup routines that don't take advantage of NTFS's features, as compared to a large organization with full time IT support. Since Microsoft is fairly close-lipped about some aspects of NTFS, you need a computer running Windows XP or better to even write to an NTFS drive, which is why no flash media comes preformatted in NTFS ... no camera, for example, can write to it ... and it can be a problem come recovery time.
FAT32 is readable and writable by just about every OS you are likely to find in devices or desktop/laptop computers. May seem minor, but when you need recovery or backups, these things sometimes matter ... you can borrow any available laptop for example.
For use as a portable flash drive storing music, you should have an absolute need for some NTFS feature. If you can't identify one, use FAT32.